Curable Composition

ABSTRACT

[Problem] There is provided a curable composition having high thixotropy and satisfactory curability by use of a non-organotin catalyst.  
     [Means to Solve] A curable composition comprising (A) a polyoxyalkylene polymer having a silicon-containing group being capable of crosslinking by forming siloxane bonds and/or a (meth)acrylate polymer having a silicon-containing group being capable of crosslinking by forming siloxane bonds, (B) a titanium chelate, and (C) an amide wax type thixotropy-imparting agent.

TECHNICAL FIELD

The present invention relates to a curable composition comprising apolyoxyalkylene polymer and/or a (meth)acrylate polymer (hereinafterreferred to as “organic polymer”) which have a silicon-containing group(hereinafter referred to as a “reactive silicon group”) being capable ofcrosslinking by forming siloxane bonds and have hydroxyl group or ahydrolyzable group bonded to the silicon atom.

BACKGROUND ART

It is known that an organic polymer having at least one reactive silicongroup in the molecule undergoes crosslinking by formation of siloxanebonds accompanying a hydrolysis reaction or the like of the reactivesilicon group with moisture or the like even at room temperature, and arubber-like cured article can be obtained.

Among the polymers having a reactive silicon group, organic polymers inwhich the main chain skeleton is a polyoxyalkylene polymer and/or a(meth)acrylate polymer are disclosed in (Patent Document 1), (PatentDocument 2) and the like. Those polymers have already been industriallyproduced, and are widely used in applications to sealants, adhesives,coatings and the like.

Curable compositions comprising the above described organic polymershaving a reactive silicon group are cured by using silanol condensationcatalysts, and usually organotin catalysts having a carbon-tin bond suchas dibutyltin bis(acetylacetonate) are widely used. However, in recentyears, toxicity of organotin compounds is pointed out, and developmentof non-organotin catalysts are demanded.

Dealcoholization type silicone compositions using organic titanates as anon-organotin catalyst are available on the market, and are widely usedin a variety of applications. This technique is disclosed in (PatentDocument 3), (Patent Document 4) and the like.

Also examples of adding an organic titanate to organic polymerscontaining a reactive silicon group are disclosed in (Patent Document5), (Patent Document 6), (Patent Document 7), (Patent Document 8),(Patent Document 9), (Patent Document 10), (Patent Document 11), (PatentDocument 12), (Patent Document 13) and (Patent Document 14).

On the other hand, as disclosed in (Patent Document 15), (PatentDocument 16), (Patent Document 17) and the like, in some cases, variousorganic thixotropy-imparting agents are added to curable compositionscomprising an organic polymer having a reactive silicon group for thepurpose of improving thixotropy.

Patent Document 1: JP-52-73998A

Patent Document 2: JP-59-74149A

Patent Document 3: JP-39-27643B (U.S. Pat. No. 3,175,993)

Patent Document 4: U.S. Pat. No. 3,334,067

Patent Document 5: JP-58-17154A (JP-3-57943B)

Patent Document 6: JP-62-146959A (JP-5-45635B)

Patent Document 7: JP-5-311063A

Patent Document 8: JP-2001-302929A

Patent Document 9: JP-2001-302930A

Patent Document 10: JP-2001-302931A

Patent Document 11: JP-2001-302934A

Patent Document 12: JP-2001-348528A

Patent Document 13: JP-2002-249672A

Patent Document 14: JP-2003-165916A

Patent Document 15: JP-6-1826A

Patent Document 16: JP-8-143850A

Patent Document 17: JP-2002-322379A

DISCLOSURE OF INVENTION Problem to be Solved by the Invention

However as a result of the investigation made by the present inventors,it was found that there is a problem that sufficient curability cannotbe obtained when a hydrogenated castor oil described in examples of theabove described (Patent Document 5), (Patent Document 12) and (PatentDocument 13) is added to a curable composition comprising a titaniumcatalyst and a polyoxyalkylene polymer and/or a (meth)acrylate polymerwhich have a reactive silicon group for the purpose of improvingthixotropy.

It is an object of the present invention to provide a curablecomposition comprising a polyoxyalkylene polymer and/or a (meth)acrylatepolymer having a reactive silicon group as a main component and havinghigh thixotropy and good curability by use of a non-organotin catalyst.

Means to Solve the Problem

As a result of a diligent investigation to solve such problems, thepresent inventors perfected the present invention by discovering that acurable composition having high thixotropy and good curability can beobtained by use of a titanium catalyst (B) having a specific structureas a curing catalyst for the above described polymer and further by useof a thixotropy-imparting agent (C) having a specific structure althoughthe catalyst concerned is a non-organotin catalyst.

Namely, the present invention relates to a curable compositioncomprising:

(A) a polyoxyalkylene polymer having a silicon-containing group beingcapable of crosslinking by forming siloxane bonds and/or a(meth)acrylate polymer having a silicon-containing group being capableof crosslinking by forming siloxane bonds,

(B) a titanium chelate represented by the following general formula (1)or (2), and

(C) an amide wax type thixotropy-imparting agent.

wherein each of n R¹s is independently a substituted or unsubstitutedhydrocarbon group having 1 to 20 carbon atoms, each of (4-n) R²s isindependently hydrogen atom or a substituted or unsubstitutedhydrocarbon group having 1 to 20 carbon atoms, each of (4-n) A¹s and(4-n) A²s is independently —R³ or —OR³ where R³ is a substituted orunsubstituted hydrocarbon group having 1 to 20 carbon atoms, n is 1, 2or 3.

wherein R², A¹ and A² are the same as defined above, R⁴ is a substitutedor unsubstituted divalent hydrocarbon group having 1 to 20 carbon atoms.

The polymer (A) is preferably a polyoxypropylene polymer having asilicon-containing group being capable of crosslinking by formingsiloxane bonds and/or a (meth)acrylate polymer having asilicon-containing group being capable of crosslinking by formingsiloxane bonds.

It is preferable that the glass transition temperature of the polymer(A) is not more than 20° C.

As a preferred mixing ratio of (A), (B) and (C), with respect to 100parts by weight of the polymer (A) are mixed the titanium chelate (B) inan amount of from 0.1 to 20 parts by weight and the amide wax typethixotropy-imparting agent (C) in an amount of from 0.1 to 20 parts byweight.

Additionally, preferred embodiments of the curable composition of thepresent invention are sealants or adhesives comprising any of the abovedescribed curable compositions.

EFFECT OF THE INVENTION

The curable composition of the present invention is high in thixotropyand excellent in curability by use of a non-organotin catalyst.

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention is then explained below in detail.

In the present invention, the polyoxyalkylene polymer having a reactivesilicon group and/or the (meth)acrylate polymer having a reactivesilicon group (hereinafter referred to as “organic polymer”) are used asthe component (A). By using the polyoxyalkylene polymer and/or the(meth)acrylate polymer as a main chain skeleton of the polymer of thecomponent (A), a satisfactory adhesion can be achieved. Additionally,when a curable composition is prepared using a titanium catalyst as thecomponent (B) of the present invention, there is a tendency thatdeep-part curability of the obtained composition is lowered depending onan added amount thereof. Accordingly, the polyoxyalkylene polymer andthe (meth)acrylate polymer as used for the component (A) of the presentinvention are preferable because they are high in moisture permeabilityand excellent in deep-part curability in the case of a one-componenttype composition, and the polyoxyalkylene polymer is more preferable.

No particular constraint is imposed on the glass transition temperatureof the organic polymer of the component (A). The glass transitiontemperature is preferably not more than 20° C., more preferably not morethan 0° C., particularly preferably not more than −20° C. If the glasstransition temperature is higher than 20° C., in some cases, a viscosityincreases and workability is lowered in wintertime or at a cold districtor flexibility and elongation of the cured article are degraded. Theabove described glass transition temperature denotes values measured byDSC.

In the present invention, the reactive silicon group contained in thepolyoxyalkylene polymer having a reactive silicon group and/or the(meth)acrylate polymer having a reactive silicon group is a group whichhas a hydroxyl group or a hydrolyzable group bonded to a silicon atom,and is capable of cross-linking through a reaction accelerated by acuring catalyst. Examples of the reactive silicon groups include groupsrepresented by the general formula (3):—(SiR⁵ _(2-b)X_(b)O)_(m)—SiR⁶ _(3-a)X_(a)  (3)wherein each of R⁵ and R⁶ is independently an alkyl group having 1 to 20carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkylgroup having 7 to 20 carbon atoms or a triorganosiloxy group representedby (R′)₃SiO—, where each of R's is independently a substituted orunsubstituted hydrocarbon group having 1 to 20 carbon atoms, each of Xsis independently hydroxyl group or a hydrolyzable group, b is 0, 1 or 2,a is 0, 1, 2 or 3, b and a are not 0 at the same time, m is 0 or aninteger of 1 to 19.

No particular constraint is imposed on the hydrolyzable group, and thehydrolyzable group may be a hydrolyzable group well known in the art.More specifically, examples of the hydrolyzable group include, forinstance, hydrogen atom, a halogen atom, an alkoxy group, an acyloxygroup, a ketoximate group, an amino group, an amide group, an acid amidegroup, an aminooxy group, a mercapto group, an alkenyloxy group and thelike. Among these groups, hydrogen atom, an alkoxy group, an acyloxygroup, a ketoximate group, an amino group, an amide group, an aminooxygroup, a mercapto group and an alkenyloxy group are preferable and analkoxy group is particularly preferable from the viewpoint that analkoxy group is moderately hydrolyzable and easily handled.

One to three hydrolyzable groups and hydroxyl groups can bond to onesilicon atom, and (a+Σb) is preferably within a range from 1 to 5. Whentwo or more hydrolyzable groups and hydroxyl groups are bonded in thereactive silicon group, they may be the same or different.

The number of silicon atoms forming the reactive silicon group is one ormore, and is preferably not more than 20 in the case of the siliconatoms connected by siloxane bonds.

Particularly reactive silicon groups represented by the general formula(4):—SiR⁶ _(3-c)X_(c)  (4)wherein R⁶ and X are the same as defined above, c is an integer of 1 to3, are preferable because they are easily available.

Examples of R⁵ and R⁶ in the above described general formulae (3) and(4) include alkyl groups such as a methyl group and an ethyl group,cycloalkyl groups such as a cyclohexyl group, aryl groups such as aphenyl group, aralkyl groups such as a benzyl group, a triorganosiloxygroup represented by (R)₃SiO— where R′ is a methyl group, a phenyl groupor the like and the like group. Of these groups, a methyl group isparticularly preferable.

More specific examples of the reactive silicon group include atrimethoxysilyl group, a triethoxysilyl group, a triisopropoxysilylgroup, a dimethoxymethylsilyl group, a diethoxymethylsilyl group and adiisopropoxymethylsilyl group. A trimethoxysilyl group, a triethoxysilylgroup and a dimethoxymethylsilyl group are more preferable and atrimethoxysilyl group is particularly preferable because these groupsare high in activity and satisfactory curability can be obtained. Alsofrom the viewpoint of storage stability, a dimethoxymethylsilyl group isparticularly preferable. Additionally, a triethoxysilyl group isparticularly preferable because the alcohol produced by the hydrolysisreaction of the reactive silicon group is ethanol and hence atriethoxysilyl group has a high safety.

The introduction of the reactive silicon group can be carried out bymethods well known in the art. More specifically, examples of suchmethods include the followings.

(a) With an organic polymer having in the molecule functional groupssuch as hydroxy groups, an organic compound having both an active groupexhibiting reactivity to the functional groups and an unsaturated groupis reacted, to yield an unsaturated group-containing organic polymer.Alternatively, an unsaturated group-containing organic polymer isobtained by copolymerization of an epoxy compound having an unsaturatedgroup with an organic polymer having in the molecule functional groupssuch as hydroxy groups. Then, a reactive silicon group-containinghydrosilane is reacted with the reaction product to be hydrosilylated.

(b) With an unsaturated group-containing organic polymer obtainedsimilarly to the method described in (a), a mercapto group- and reactivesilicon group-containing compound is reacted.

(c) With an organic polymer having in the molecule functional groupssuch as hydroxy groups, epoxy groups and isocyanate groups, a compoundhaving a functional group exhibiting reactivity to the functional groupsand a reactive silicon group is reacted.

Among the above methods, the method described in (a) or the methoddescribed in (c) in which a hydroxy group-terminated polymer is reactedwith an isocyanate group- and reactive silicon group-containing compoundis preferable because the method provides a high conversion rate at arelatively short reaction time. Additionally, the method described in(a) is particularly preferable because the reactive silicongroup-containing organic polymer obtained by the method described in (a)is lower in viscosity and more satisfactory in workability than anorganic polymer obtained by the method described in (c), and an organicpolymer obtained by the method described in (b) is strong in odor due tomercaptosilane.

Examples of the hydrosilane compound used in the method described in (a)include halogenated silanes such as trichlorosilane,methyldichlorosilane, dimethylchlorosilane and phenyldichlorosilane;alkoxysilanes such as trimethoxysilane, triethoxysilane,methyldiethoxysilane, methyldimethoxysilane and phenyldimethoxysilane;acyloxysilanes such as methyldiacetoxysilane and phenyldiacetoxysilane;ketoximate silanes such as bis(dimethylketoximate)methylsilane andbis(cyclohexylketoximate)methylsilane and the like. However, thehydrosilane compound used in the method described in (a) is not limitedto these compounds. Of these compounds, halogenated silanes andalkoxysilanes are preferable and in particular, alkoxysilanes are mostpreferable because the obtained curable compositions are moderatelyhydrolyzable and easily handled. Of the alkoxysilanes,methyldimethoxysilane is particularly preferable because it is easilyavailable and curability, storage stability, elongation property andtensile strength of the curable composition containing the obtainedorganic polymer are high.

Examples of the synthesis method described in (b) include a method inwhich a mercapto group- and reactive silicon group-containing compoundis introduced into the sites on the unsaturated bonds of an organicpolymer by means of a radical addition reaction in the presence of aradical initiator and/or a radical generating source; however, thesynthesis method concerned is not limited to these methods. Examples ofthe above described mercapto group- and reactive silicongroup-containing compound include γ-mercaptopropyltrimethoxysilane,γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropyltriethoxysilane,γ-mercaptopropylmethyldiethoxysilane, mercaptomethyltrimethoxysilane,mercaptomethyltriethoxysilane, (mercaptomethyl)methyldiethoxysilane,(mercaptomethyl)methyldimethoxysilane and the like; however, themercapto group- and reactive silicon group-containing compound is notlimited to these compounds.

Examples of the method, of the methods described in (c), in which ahydroxy-terminated polymer is reacted with an isocyanate group- andreactive silicon group-containing compound include a method disclosed inJapanese Patent Laid-Open No. 3-47825; however, the method concerned isnot limited to these methods. Examples of the above described isocyanategroup- and reactive silicon group-containing compound includeγ-isocyanatopropyltrimethoxysilane,γ-isocyanatopropylmethyldimethoxysilane,γ-isocyanatopropyltriethoxysilane,γ-isocyanatopropylmethyldiethoxysilane,(isocyanatomethyl)trimethoxysilane, (isocyanatomethyl)triethoxysilane,(isocyanatomethyl)dimethoxymethylsilane,(isocyanatomethyl)diethoxymethylsilane and the like; however, thecompound concerned is not limited to these compounds.

In the case of silane compounds such as trimethoxysilane in which threehydrolyzable groups are bonded to one silicon atom, in some cases,disproportionation reaction proceeds. If disproportionation reactionproceeds, a very dangerous compound like dimethoxysilane is generated.However in the cases of γ-mercaptopropyltrimethoxysilane andγ-isocyanatopropyltrimethoxysilane, such a disproportionation reactiondoes not proceed. Accordingly, when using, as a silicon-containinggroup, a group such as a trimethoxysilyl group in which threehydrolyzable groups are bonded to one silicon atom, it is preferable toemploy the synthesis method of (b) or (c).

The reactive silicon group-containing organic polymer may be a straightchain or may have branches, and the number average molecular weightthereof, measured by GPC relative to polystyrene standard, is preferablyof the order of 500 to 100,000, more preferably 1,000 to 50,000,particularly preferably 3,000 to 30,000. When the number averagemolecular weight is less than 500, it tends to be disadvantageous fromthe viewpoint of an elongation property of the cured article, while whenthe number average molecular weight exceeds 100,000, it tends to bedisadvantageous from the viewpoint of workability because the viscositybecomes high.

For the purpose of obtaining a rubber-like cured article having a highstrength, a high elongation property and a low elastic modulus, it isrecommended that the number of reactive silicon groups contained in theorganic polymer is, on average in one polymer molecule, at least one,and preferably 1.1 to 5. When the average number of reactive silicongroups contained in the molecule is less than 1, the curability becomesinsufficient, and hence a satisfactory rubber elasticity behavior canhardly be exhibited. The reactive silicon group may be located at theterminal of the main chain or at the terminal of the side chain, or atthe both in the organic polymer molecule chain. In particular, when thereactive silicon group is located only at the terminal of the mainchain, the effective network content in the organic polymer componentcontained in the finally formed cured article becomes large, so that itbecomes easier to obtain a rubber-like cured article having a highstrength, a high elongation property and a low elastic modulus.

The polyoxyalkylene polymer is essentially a polymer having therepeating units represented by the general formula (5):—R⁷—O—  (5)wherein R⁷ is a linear or branched alkylene group having 1 to 14 carbonatoms. In the general formula (5), R⁷ is preferably a linear or branchedalkylene group having 1 to 14 carbon atoms, and more preferably 2 to 4carbon atoms. Examples of the repeating units represented by the generalformula (5) include:—CH₂O—, —CH₂CH₂O—, —CH₂CH(CH₃)O—, —CH₂CH(C₂H₅)O—, —CH₂C(CH₃)₂₋₀—,—CH₂CH₂CH₂CH₂O—,and the like. The main chain skeleton of the polyoxyalkylene polymer maybe formed of either only one type of repeating unit or two or more typesof repeating units. In particular, in the case where the polymer is usedfor a sealant and the like, it is preferable that the main chainskeleton is formed of a polymer containing as the main component apropyleneoxide polymer because a polymer having such a main chainskeleton is amorphous and relatively low in viscosity.

Examples of the synthesis method of the polyoxyalkylene polymer includea polymerization method in the presence of an alkaline catalyst such asKOH; a polymerization method in the presence of a transition metalcompound-porphyrin complex catalyst prepared by reacting anorganoaluminum compound with porphyrin, disclosed in Japanese PatentLaid-Open No. 61-215623; polymerization methods in the presence ofcomposite metal cyanide complex catalysts, disclosed in Japanese PatentExamined Publication Nos. 46-27250 and 59-15336, and U.S. Pat. Nos.3,278,457, 3,278,458, 3,278,459, 3,427,256, 3,427,334, 3,427,335 and thelike; a polymerization method in the presence of a catalyst composed ofa polyphosphazene salt disclosed in Japanese Patent Laid-Open No.10-273512, and a polymerization method in the presence of a catalystcomposed of a phosphazene compound disclosed in Japanese PatentLaid-Open No. 11-060722. However, the method concerned is not limited tothese methods.

Examples of the preparation method of the reactive silicongroup-containing polyoxyalkylene polymer of the present inventioninclude the methods disclosed in Japanese Patent Examined PublicationNos. 45-36319 and 46-12154, Japanese Patent Laid-Open Nos. 50-156599,54-6096, 55-13767, 55-13468 and 57-164123, Japanese Patent ExaminedPublication No. 3-2450, and U.S. Pat. Nos. 3,632,557, 4,345,053,4,366,307 and 4,960,844; and the methods of preparing polyoxyalkylenepolymers each having a high molecular weight such that the numberaverage molecular weight is not less than 6,000 and a narrow molecularweight distribution such that the Mw/Mn value is not more than 1.6,disclosed in Japanese Patent Laid-Open Nos. 61-197631, 61-215622,61-215623, 61-218632, 3-72527, 3-47825 and 8-231707. However, the methodconcerned is not limited to these methods.

The above described reactive silicon group-containing polyoxyalkylenepolymers may be used either each alone or in combinations of two or morethereof.

On the other hand, no particular constraint is imposed on the(meth)acrylate monomers constituting the main chains of the abovedescribed (meth)acrylate polymers, and various types can be used.Examples of the monomers concerned include (meth)acrylic acid monomerssuch as (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate,n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl(meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate,n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl(meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate,2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate,dodecyl (meth)acrylate, phenyl (meth)acrylate, tolyl (meth)acrylate,benzyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 3-methoxybutyl(meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl(meth)acrylate, stearyl (meth)acrylate, glycidyl (meth)acrylate,2-aminoethyl (meth)acrylate, γ-(methacryloyloxypropyl)trimethoxysilane,γ-(methacryloyloxypropyl)γdimethoxymethylsilane,methacryloyloxymethyltrimethoxysilane,methacryloyloxymethyltriethoxysilane,methacryloyloxymethyldimethoxymethylsilane,methacryloyloxymethyldiethoxymethylsilane, ethylene oxide adduct of(meth)acrylate, trifluoromethylmethyl (meth)acrylate,2-trifluoromethylethyl (meth)acrylate, 2-perfluoroethylethyl(meth)acrylate, 2-perfluoroethyl-2-perfluorobutylethyl (meth)acrylate,perfluoroethyl (meth)acrylate, trifluoromethyl (meth)acrylate,bis(trifluoromethylmethyl)(meth)acrylate,2-trifluoromethyl-2-perfluoroethylethyl (meth)acrylate,2-perfluorohexylethyl (meth)acrylate, 2-perfluorodecylethyl(meth)acrylate and 2-perfluorohexadecylethyl (meth)acrylate. For theabove described (meth)acrylate polymers, (meth)acrylate monomers can becopolymerized with the following vinyl monomers. Examples of the vinylmonomers concerned include styrene monomers such as styrene,vinyltoluene, α-methylstyrene, chlorostyrene, styrenesulfonic acid andthe salts thereof; fluorine-containing vinyl monomers such asperfluoroethylene, perfluoropropylene and fluorinated vinylidene;silicon-containing vinyl monomers such as vinyltrimethoxysilane andvinyltriethoxysilane; maleic anhydride, maleic acid, and monoalkylesters and dialkyl esters of maleic acid; fumaric acid, and monoalkylesters and dialkyl esters of fumaric acid; maleimide monomers such asmaleimide, methylmaleimide, ethylmaleimide, propylmaleimide,butylmaleimide, hexylmaleimide, octylmaleimide, dodecylmaleimide,stearylmaleimide, phenylmaleimide and cyclohexylmaleimide; nitrilegroup-containing vinyl monomers such as acrylonitrile andmethacrylonitrile; amide group-containing vinyl monomers such asacrylamide and methacrylamide; vinyl esters such as vinyl acetate, vinylpropionate, vinyl pivalate, vinyl benzoate and vinyl cinnamate; alkenessuch as ethylene and propylene; conjugated dienes such as butadiene andisoprene; and vinyl chloride, vinylidene chloride, allyl chloride andallyl alcohol. These monomers may be used each alone or two or more ofthese monomers may be copolymerized. Among these, from the viewpoint ofthe physical properties of the products, polymers formed of styrenemonomers and (meth)acrylic acid monomers are preferable. More preferableare the (meth)acryl polymers formed of acrylate monomers andmethacrylate monomers, and particularly preferable are the acrylpolymers formed of acrylate monomers. For general constructionapplications, the butyl acrylate monomers are further preferable becausecompositions concerned each are required to have physical propertiesincluding a low viscosity, and the cured articles each are required tohave physical properties including a low modulus, a high elongationproperty, a weather resistance and a heat resistance. On the other hand,for applications to vehicles and the like where oil resistance isrequired, copolymers made of ethyl acrylate as the main material arefurther preferable. The copolymers made of ethyl acrylate as the mainmaterial are excellent in oil resistance, but slightly tend to be poorin low-temperature property (low-temperature resistance); for thepurpose of improving the low-temperature property thereof, a part ofethyl acrylates can be replaced with butyl acrylate. However, with theincrease of the ratio of butyl acrylate, the satisfactory oil resistancecomes to be degraded, so that for the application to the use requiringoil resistance, the ratio of butyl acrylate is set preferably to notmore than 40%, and more preferably to not more than 30%. Additionally,it is also preferable to use 2-methoxyethyl acrylate and 2-ethoxyethylacrylate which have side chain alkyl groups containing oxygen atomsintroduced for the purpose of improving the low-temperature property andthe like without degrading the oil resistance; in this connection, it isto be noted that the introduction of alkoxy groups having an ether bondin the side chains tends to degrade the heat resistance, so that theratio of such an acrylate is preferably not more than 40% when heatresistance is required. It is possible to obtain appropriate polymers byvarying the ratio in consideration of required physical properties suchas oil resistance, heat resistance and low-temperature propertyaccording to the various applications and the required objectives.Examples of the polymers excellent in the balance between the physicalproperties including the oil resistance, heat resistance,low-temperature property and the like include a copolymer of ethylacrylate/butyl acrylate/2-methoxyethyl acrylate (40 to 50/20 to 30/30 to20 in a ratio by weight), this copolymer imposing no constraint on thepolymers concerned. In the present invention, these preferable monomerscan be copolymerized with other monomers, and moreover, blockcopolymerized with other monomers. In such cases, it is preferable thatthe preferable monomers are contained in an amount of not less than 40%in a ratio by weight. Incidentally, it is to be noted that in the aboveform of presentation, for example, “(meth)acrylic acid” means acrylicacid and/or methacrylic acid.

No particular constraint is imposed on the synthesis methods of the(meth)acrylate polymers, and the methods well known in the art can beapplied. However, polymers obtained by the usual free radicalpolymerization methods using azo compounds and peroxides aspolymerization initiators have a problem such that the molecular weightdistribution values of the polymers are generally as large as not lessthan 2 and the viscosities of the polymers are high. Accordingly, it ispreferable to apply living radical polymerization methods for thepurpose of obtaining (meth)acrylate polymers being narrow in molecularweight distribution and low in viscosity, and moreover, havingcross-linking functional groups at the molecular chain terminals in ahigh ratio.

Among “the living radical polymerization methods,” “the atom transferradical polymerization method” in which (meth)acrylate monomers arepolymerized by use of an organic halogenated compound or a halogenatedsulfonyl compound as an initiator and a transition metal complex as acatalyst has, in addition to the features of the above described “livingradical polymerization methods,” features such that the obtained polymerhas halogen atoms at the terminals relatively favorable for thefunctional group conversion reaction and freedom for designing theinitiator and the catalyst is wide, so that the atom transfer radicalpolymerization method is further preferable as a method for preparing(meth)acrylate polymers having particular functional groups. Examples ofthe atom transfer radical polymerization method include the methodreported by Matyjaszewski et al. in Journal of the American ChemicalSociety (J. Am. Chem. Soc.), Vol. 117, p. 5614 (1995).

As a preparation method of a reactive silicon group-containing(meth)acrylate polymer, for example, Japanese Patent ExaminedPublication Nos. 3-14068 and 4-55444, and Japanese Patent Laid-Open No.6-211922 and the like disclose preparation methods according to the freeradical polymerization methods by using chain transfer agents.Additionally, Japanese Patent Laid-Open No. 9-272714 and the likedisclose a preparation method according to the atom transfer radicalpolymerization method. However, the preparation method concerned is notlimited to these methods.

The above described reactive silicon group-containing (meth)acrylatepolymers may be used either each alone or in combinations of two or morethereof.

These reactive silicon group-containing organic polymers may be usedeither each alone or in combinations of two or more thereof.Specifically, there can be used organic polymers formed by blending twoor more polymers selected from the group consisting of the reactivesilicon group-containing polyoxyalkylene polymers, the reactive silicongroup-containing saturated hydrocarbon polymers and the reactive silicongroup-containing (meth)acrylate polymers.

The preparation methods of the organic polymers formed by blending thereactive silicon group-containing polyoxyalkylene polymers with thereactive silicon group-containing (meth)acrylate polymers are proposedin Japanese Patent Laid-Open Nos. 59-122541, 63-112642, 6-172631,11-116763 and the like. However, the preparation method concerned is notlimited to these methods. A preferable specific example is a preparationmethod in which a reactive silicon group-containing polyoxyalkylenepolymer is blended with a copolymer formed of two (meth)acrylate monomerunits: one (meth)acrylate monomer unit has the reactive silicon groupsand alkyl groups having 1 to 8 carbon atoms, and the molecular chain issubstantially represented by the following general formula (6):—CH₂—C(R⁸)(COOR⁹)—  (6)wherein R⁸ represents hydrogen atom or a methyl group, and R⁹ representsan alkyl group having 1 to 8 carbon atoms; and the other (meth)acrylatemonomer unit has alkyl groups having 10 or more carbon atoms and isrepresented by the following general formula (7):—CH₂—C(R⁸)(COOR¹⁰)—  (7)wherein R⁸ is the same as defined above, and R¹⁰ represents an alkylgroup having 10 or more carbon atoms.

In the above general formula (6), examples of R⁹ include alkyl groupshaving 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms and furtherpreferably 1 to 2 carbon atoms such as a methyl group, an ethyl group, apropyl group, a n-butyl group, a t-butyl group and a 2-ethylhexyl group.It is also to be noted that the alkyl group of R⁹ may represent eitherone type or admixtures of two or more types.

In the above general formula (7), examples of R¹⁰ include long chainalkyl groups having 10 or more carbon atoms, usually 10 to 30 carbonatoms, and preferably 10 to 20 carbon atoms such as a lauryl group, atridecyl group, a cetyl group, a stearyl group and a behenyl group. Itis also to be noted that the alkyl group of R¹⁰ may represent, similarlyto R⁹, either one type or admixtures of two or more types.

The molecular chains of the above described (meth)acrylate copolymersare substantially formed of the monomer units represented by formulas(6) and (7): “substantially” as referred to here means that in thecopolymer concerned, the sum content of the monomer unit of formula (6)and the monomer unit of formula (7) exceeds 50 wt %. The sum content ofthe monomer units of formulas (6) and (7) is preferably not less than 70wt %.

Additionally, the abundance ratio by weight of the monomer unit offormula (6) to the monomer unit of formula (7) is preferably 95:5 to40:60, and further preferably 90:10 to 60:40.

Examples of the monomer units other than the monomer units of formulas(6) and (7) which may be contained in the above described copolymerinclude α,β-unsaturated carboxylic acids such as acrylic acid andmethacrylic acid; monomers containing amide groups such as acrylamide,methacrylamide, N-methylolacrylamide and N-methylolmethacrylamide,monomers containing epoxy groups such as glycidylacrylate andglycidylmethacrylate, and monomers containing amino groups such asdiethylaminoethyl acrylate, diethylaminoethyl methacrylate andaminoethyl vinyl ether; and monomer units derived from acrylonitrile,styrene, α-methylstyrene, alkyl vinyl ethers, vinyl chloride, vinylacetate, vinyl propionate and ethylene.

Moreover, for the preparation method of the organic polymers formed byblending the (meth)acrylate polymers having the reactive siliconfunctional groups, there can be used additional methods in which(meth)acrylate monomers are polymerized in the presence of a reactivesilicon group-containing polyoxypropylene polymer. These methods aredisclosed specifically in Japanese Patent Laid-Open Nos. 59-78223,60-228516, 60-228517 and the like. However, the method concerned is notlimited to these methods.

The main chain skeleton of the organic polymer of the present inventionmay include other components such as binding urethane components as faras such inclusion does not largely impair the effect of the presentinvention.

No particular constraint is imposed on the binding urethane components.Examples thereof include groups (hereinafter referred to as amidesegments) formed by a reaction of an isocyanate group with an activehydrogen group.

The above described amide segments are groups represented by the generalformula (8):—NR¹¹—C(═O)—  (8)wherein R¹¹ represents hydrogen atom or a substituted or unsubstitutedorganic group.

Examples of the above described amide segments include a urethane groupformed by a reaction of an isocyanate group with hydroxyl group; a ureagroup formed by a reaction of an isocyanate group with an amino group; athiourethane group formed by a reaction of an isocyanate group with amercapto group; and the like. Additionally, in the present invention,groups formed by further reaction of an active hydrogen in the urethanegroup, urea group or thiourethane group with an isocyanate group areincluded in the groups of the general formula (8).

Example of an industrially easy method of preparing an organic polymerhaving both of an amide segment and a reactive silicon group is a methodin which after or at the same time of reacting an organic polymer havingan active hydrogen-containing group at the terminal with an excessiveamount of polyisocyanate compound to yield a polymer having isocyanategroups at the terminals of polyurethane main chains, a part or the wholeof isocyanate groups are reacted with a W group of the silicon compoundrepresented by the general formula (9):W—R¹²—SiR⁶ _(3-c)X_(c)  (9)wherein R⁶, X and c are the same as defined above; R¹² is a divalentorganic group, more preferably a substituted or unsubstituted divalenthydrocarbon group having 1 to 20 carbon atoms; W is an activehydrogen-containing group selected from hydroxyl group, a carboxylgroup, a mercapto group and an amino group (unsubstituted ormono-substituted). Known methods of preparing organic polymers inrelation to this preparation method are disclosed in Japanese PatentExamined Publication No. 46-12154 (U.S. Pat. No. 3,632,557), JapanesePatent Laid-Open Nos. 58-109529 (U.S. Pat. No. 4,374,237), 62-13430(U.S. Pat. No. 4,645,816), 8-53528 (EP Patent No. 0676403), and10-204144 (EP Patent No. 0831108), Japanese Patent Laid-Open No.2003-508561 (U.S. Pat. No. 6,197,912), Japanese Patent Laid-Open Nos.6-211879 (U.S. Pat. No. 5,364,955), 10-53637 (U.S. Pat. No. 5,756,751),11-100427, 2000-169544, 2000-169545, and 2002-212415, Japanese PatentNo. 3313360, U.S. Pat. No. 4,067,844, U.S. Pat. No. 3,711,445, JapanesePatent Laid-Open No. 2001-323040 and the like.

Additionally, there are methods of preparation by reacting an organicpolymer having an active hydrogen-containing group at the terminal witha reactive silicon group-containing isocyanate compound represented bythe general formula (10):O═C═N—R¹²—SiR⁶ _(3-c)X_(c)  (10)wherein R⁶, R¹², X and c are the same as defined above. Known methods ofpreparing organic polymers in relation to this preparation method aredisclosed in Japanese Patent Laid-Open Nos. 11-279249 (U.S. Pat. No.5,990,257), 2000-119365 (U.S. Pat. No. 6,046,270), 58-29818 (U.S. Pat.No. 4,345,053), 3-47825 (U.S. Pat. No. 5,068,304), 11-60724,2002-155145, 2002-249538, WO03/018658, WO03/059981 and the like.

Examples of the organic polymers having an active hydrogen-containinggroup at the terminal include oxyalkylene polymers (polyether polyols)having hydroxyl group at the terminal and polyacryl polyols. Among them,polyether polyols are preferable because a viscosity of the obtainedorganic polymers is low, and workability, adhesion and deep-partcurability are good. Additionally polyacryl polyols are more preferablebecause weather resistance and heat resistance of the cured articlesobtained from the organic polymers are good.

Polyether polyols prepared by any of preparation methods can be used,and preferred are polyether polyols having at least 0.7 hydroxyl groupper a molecular terminal on average of the whole molecules.Specifically, examples thereof are oxyalkylene polymers prepared byusing conventional alkali metal catalysts, oxyalkylene polymers preparedby reacting an initiator such as a polyhydroxy compound having at leasttwo hydroxyl groups with alkylene oxide in the presence of a compositemetal cyanide complex and cesium, and the like.

Of the above described polymerization methods, the method using acomposite metal cyanide complex is preferable because oxyalkylenepolymers having a lower degree of unsaturation, a narrow Mw/Mn, a lowerviscosity and high acid resistance and weather resistance can beobtained.

Examples of the above described polyacryl polyols include polyols havingan alkyl (meth)acrylate (co)polymer skeleton and containing hydroxygroups in the molecule. As the synthesis method to produce thesepolymers, the living radical polymerization method is preferable becausethis method can lead to narrow molecular weight distributions and lowviscosities, and the atom transfer radical polymerization method isfurther preferable. Additionally, it is preferable to use a polymerbased on the so-called SGO process which is obtained by continuouslyblock-polymerizing an alkyl acrylate monomer at a high temperature undera high pressure, as described in Japanese Patent Laid-Open No.2001-207157. Specifically, examples thereof include UH-2000 produced byToagosei Co., Ltd., and the like.

Examples of the polyisocyanate compound include aromatic polyisocyanatessuch as toluene (tolylene) diisocyanate, diphenylmethane diisocyanateand xylylene diisocyanate; and aliphatic polyisocyanates such asisophorone diisocyanate and hexamethylene diisocyanate.

No particular constraint is imposed on the silicon compound of thegeneral formula (9). Specifically, examples thereof include silaneshaving amino group such as γ-aminopropyltrimethoxysilane,N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane,γ-(N-phenyl)aminopropyltrimethoxysilane,N-ethylaminoisobutyltrimethoxysilane,N-cyclohexylaminomethyltriethoxysilane,N-cyclohexylaminomethyldiethoxymethylsilane andN-phenylaminomethyltrimethoxysilane; silanes having hydroxy group suchas γ-hydroxypropyltrimethoxysilane; silanes having mercapto group suchas γ-mercaptopropyltrimethoxysilane; and the like. Additionally, asdescribed in Japanese Patent Laid-Open Nos. 6-211879 (U.S. Pat. No.5,364,955), 10-53637 (U.S. Pat. No. 5,756,751), 10-204144 (EP Patent No.0831108), 2000-169544 and 2000-169545, there can be used Michaeladdition reaction products of various α,β-unsaturated carbonyl compoundsand primary amino group-containing silanes and Michael addition reactionproducts of various (meth)acryloyl group-containing silanes and primaryamino group-containing compounds as the silicon compounds of the generalformula (9).

No particular constraint is imposed on the reactive silicongroup-containing isocyanate compound of the general formula (10).Specifically, examples thereof includeγ-trimethoxysilylpropylisocyanate, γ-triethoxysilylpropylisocyanate,γ-methyldimethoxysilylpropylisocyanate,γ-methyldiethoxysilylpropylisocyanate, trimethoxysilylmethylisocyanate,diethoxymethylsilylmethylisocyanate and the like. Additionally, asdescribed in Japanese Patent Laid-Open No. 2000-119365 (U.S. Pat. No.6,046,270), a compound obtained by reacting the silicon compound of thegeneral formula (9) with an excessive amount of the above describedpolyisocyanate compound can be used as the reactive silicongroup-containing isocyanate compound of the general formula (10).

When amide segments contained in the main chain skeleton of the organicpolymer of the present invention are abundant, the viscosity of theorganic polymer becomes high and forms a composition poor in workabilityas the case may be. On the other hand, curability of the composition ofthe present invention tends to be enhanced by the amide segmentscontained in the main chain skeleton of the organic polymer. When theorganic polymer having amide segments in its main chain skeleton is usedas the component (A), the composition prepared in a combination of thepolymer with the component (B) of the present invention is preferablebecause the composition has a quicker curability by use of anon-organotin catalyst. Accordingly when the amide segments arecontained in the main chain skeleton of the organic polymer, the averagenumber of amide segments per molecule is preferably from 1 to 10, morepreferably from 1.5 to 7, particularly preferably from 2 to 5. When thenumber of amide segments is less than 1, in some cases, curabilitybecomes insufficient, and when the number of amide segments is more than10, the viscosity of the organic polymer becomes high and forms acomposition poor in workability.

In the present invention, the titanium chelate represented by thefollowing general formula (1) or (2) is used as the component (B).

wherein each of n R¹s is independently a substituted or unsubstitutedhydrocarbon group having 1 to 20 carbon atoms, each of (4-n) R²s isindependently hydrogen atom or a substituted or unsubstitutedhydrocarbon group having 1 to 20 carbon atoms, each of (4-n) A¹s and(4-n) A²s is independently —R³ or —OR³ where R³ is a substituted orunsubstituted hydrocarbon group having 1 to 20 carbon atoms, n is 1, 2or 3.

wherein R², A¹ and A² are the same as defined above, R⁴ is a substitutedor unsubstituted divalent hydrocarbon group having 1 to 20 carbon atoms.

This titanium chelate functions as a curing catalyst for the organicpolymer of the component (A). Organotin compounds such as dibutyltindilaurate and dibutyltin bis(acetylacetonate) have been so far used as acuring catalyst for the reactive silicon group-containing organicpolymer of the component (A), but by using the titanium chelate (B) ofthe present invention, a curable composition having practical curingproperties can be obtained although the catalyst concerned is anon-organotin catalyst. Further, a curable composition having goodcurability and storage stability can be obtained as compared with thecase of using other titanium catalysts having no chelate ligands.Further as compared with the case of using other curing catalysts suchas organotin catalysts, adhesion to organic articles to be hardlyadhered such as acrylic resins can be enhanced.

Examples of the titanium chelates of the general formula (1) or (2)include titanium dimethoxidebis(ethylacetoacetate), titaniumdimethoxidebis(acetylacetonate), titaniumdiethoxidebis(ethylacetoacetate), titaniumdiethoxidebis(acetylacetonate), titaniumdiisopropoxidebis(ethylacetoacetate), titaniumdiisopropoxidebis(methylacetoacetate), titaniumdiisopropoxidebis(t-butylacetoacetate), titaniumdiisopropoxidebis(methyl-3-oxo-4,4-dimethylhexanoate), titaniumdiisopropoxidebis(ethyl-3-oxo-4,4,4-trifluorobutanoate), titaniumdiisopropoxidebis(acetylacetonate), titaniumdiisopropoxidebis(2,2,6,6-tetramethyl-3,5-heptanedionate), titaniumdi-n-butoxidebis(ethylacetoacetate), titaniumdi-n-butoxidebis(acetylacetonate), titaniumdiisobutoxidebis(ethylacetoacetate), titaniumdiisobutoxidebis(acetylacetonate), titaniumdi-t-butoxidebis(ethylacetoacetate), titaniumdi-t-butoxidebis(acetylacetonate), titaniumdi-2-ethylhexoxidebis(ethylacetoacetate), titaniumdi-2-ethylhexoxidebis(acetylacetonate), titaniumbis(1-methoxy-2-propoxide)bis(ethylacetoacetate), titaniumbis(3-oxo-2-butoxide)bis(ethylacetoacetate), titaniumbis(3-diethylaminopropoxide)bis(ethylacetoacetate), titaniumtriisopropoxide(ethylacetoacetate), titaniumtriisopropoxide(diethylmalonate), titaniumtriisopropoxide(allylacetoacetate), titaniumtriisopropoxide(methacryloxyethylacetoacetate),1,2-dioxyethanetitaniumbis(ethylacetoacetate),1,3-dioxypropanetitaniumbis(ethylacetoacetate),2,4-dioxypentanetitaniumbis(ethylacetoacetate),2,4-dimethyl-2,4-dioxypentanetitaniumbis(ethylacetoacetate), titaniumbis(trimethylsiloxy)bis(ethylacetoacetate), titaniumbis(trimethylsiloxy)bis(acetylacetonate) and the like. Of these titaniumchelates, specifically preferred are titaniumdiethoxidebis(ethylacetoacetate), titaniumdiethoxidebis(acetylacetonate), titaniumdiisopropoxidebis(ethylacetoacetate), titaniumdiisopropoxidebis(acetylacetonate), titaniumdibutoxidebis(ethylacetoacetate) and titaniumdibutoxidebis(acetylacetonate) because those titanium chelates areeasily available and also from the viewpoint of catalytic activity. Morepreferred are titanium diethoxidebis(ethylacetoacetate), titaniumdiisopropoxidebis(ethylacetoacetate) and titaniumdibutoxidebis(ethylacetoacetate), and most preferred is titaniumdiisopropoxidebis(ethylacetoacetate).

Preferred examples of the chelating agents capable of forming chelateligands of the above described titanium chelates include β-diketonessuch as acetylacetone and 2,2,4,4-tetramethyl-3,5-heptanedion;β-ketoesters such as methyl acetoacetate, ethyl acetoacetate, t-butylacetoacetate, allyl acetoacetate, (2-methacryloxyethyl)acetoacetate,methyl 3-oxo-4,4-dimethylhexanoate and ethyl3-oxo-4,4,4-trifluorobutanoate; and β-diesters such as dimethyl malonateand diethyl malonate from the viewpoint of curability. Among them,β-diketones and β-ketoesters are more preferred from the viewpoint ofcurability and storage stability, and β-ketoesters are particularlypreferred. Specifically acetylacetone, methyl acetoacetate and ethylacetoacetate are more preferred from the viewpoint of curability andstorage stability and because those compounds are easily available, andethyl acetoacetate is most preferable. Also when two or more chelateligands are present, those chelate ligands may be the same or different.

As a method of adding the above described titanium chelates, in additionto a method of directly adding the above exemplified titanium chelates,there can be used a method of adding a chelating agent such as ethylacetoacetate and a titanium compound reactable with the chelating agentsuch as titanium tetraisopropoxide or titanium dichloride diisopropoxideto the composition of the present invention to subject the titaniumcompound to chelating in a composition in situ.

The titanium chelates of the component (B) may be used either each aloneor in combinations of two or more thereof.

The used amount of the component (B) is preferably from 0.1 to 20 partsby weight, and more preferably from 0.5 to 15 parts by weight,especially preferably from 1 to 10 parts by weight with respect to 100parts by weight of the component (A). When the blended amount of thecomponent (B) is less than the above described ranges, sometimes thepractical curing rate cannot be obtained, and the curing reaction hardlyproceeds to a sufficient extent. On the other hand, when the blendedamount of the component (B) exceeds the above described ranges, there isa tendency that the work life becomes too short and the workability isdegraded.

In the present invention, a titanium catalyst other than the component(B) can be used to an extent not to degrade the effect of the presentinvention. Examples thereof include titanium alkoxides such as titaniumtetramethoxide, titanium tetraethoxide, titanium allyloxide, titaniumtetra-n-propoxide, titanium tetraisopropoxide, titaniumtetra-n-butoxide, titanium tetraisobutoxide, titaniumtetra-sec-butoxide, titanium tetra-t-butoxide, titaniumtetra-n-pentyloxide, titanium tetracyclopentyloxide, titaniumtetrahexyloxide, titanium tetracyclohexyloxide, titaniumtetrabenzyloxide, titanium tetraoctyloxide, titaniumtetrakis(2-ethylhexyloxide), titanium tetradecyloxide, titaniumtetradodecyloxide, titanium tetrastearyloxide, titanium tetrabutoxidedimer, titanium tetrakis(8-hydroxyoctyloxide), titaniumdiisopropoxidebis(2-ethyl-1,3-hexanediolate), titaniumbis(2-ethylhexyloxy)bis(2-ethyl-1,3-hexanediolate), titaniumtetrakis(2-chloroethoxide), titanium tetrakis(2-bromoethoxide), titaniumtetrakis(2-methoxyethoxide), titanium tetrakis(2-ethoxyethoxide),titanium butoxidetrimethoxide, titanium dibutoxidedimethoxide, titaniumbutoxidetriethoxide, titanium dibutoxidediethoxide, titaniumbutoxidetriisopropoxide, titanium dibutoxidediisopropoxide, titaniumtetraphenoxide, titanium tetrakis(o-chlorophenoxide), titaniumtetrakis(m-nitrophenoxide) and titanium tetrakis(p-methylphenoxide);titanium acylates such as titanium acrylate triisopropoxide, titaniummethacrylate triisopropoxide, titanium dimethacrylate diisopropoxide,titanium trimethacrylate isopropoxide, titanium hexanoatetriisopropoxide and titanium stearate triisopropoxide; halogenatedtitanates such as titanium chloride triisopropoxide, titanium dichloridediisopropoxide, titanium isopropoxide trichloride, titanium bromidetriisopropoxide, titanium fluoride triisopropoxide, titanium chloridetriethoxide and titanium chloride tributoxide; other titanates such astitanium diisopropoxidebis(triethanolaminate), titaniumtetrakis(ethylacetoacetate), titanium tetrakis(acetylacetonate),titanium tris(dioctylphosphate)isopropoxide, titaniumtris(dodecylbenzenesulfonate)isopropoxide anddihydroxytitaniumbislactate; and the like.

In the present invention, an amide wax type thixotropy-imparting agentis used as the component (C). By adding this amide wax typethixotropy-imparting agent to the curable composition of the presentinvention, thixotropy, namely, a property such that a viscosity is lowunder the condition of a high shear rate and is high under the conditionof a low shear rate, is imparted to the composition.

When conventional organotin compounds are used as a curing catalyst,curability does not depend on a kind of a thixotropy-imparting agent tobe added, and nearly equal curability is exhibited. However in the caseof use of titanium compounds as a curing catalyst, more satisfactorycurability is exhibited when the amide wax type thixotropy-impartingagent (C) of the present invention is used, as compared with otherthixotropy-imparting agents such as hydrogenated castor oil.Particularly by combination with the titanium chelate (B) of the presentinvention, a composition having both of thixotropy and curability can beobtained.

No particular constraint is imposed on the amide wax typethixotropy-imparting agent as long as it is a compound in the form ofwax having an amide group. Preferred are compounds having a meltingpoint of not less than 30° C. and obtained by a reaction of a fatty acidwith an aliphatic amine and/or an alicyclic amine because they areeasily available and has a high effect of imparting thixotropy. Themelting point is more preferably not less than 50° C., and particularlypreferably not less than 70° C. If the melting point is less than 30°C., in some cases, an effect of imparting thixotropy is not sufficient.

Examples of commercially available amide wax type thixotropy-impartingagents include Disparlon 6500, Disparlon 6600, Disparlon 6900-20X,Disparlon 6900-20XN, Disparlon 6900-10X, Disparlon 6810-20X, Disparlon6840-10X, Disparlon 6850-20X, Disparlon A603-20X and Disparlon A650-20X(all are products of Kusumoto Chemicals, Ltd.); A-S-A T-1700 and A-S-AT-1800 (all are products of Itoh Oil Chemicals Co, Ltd.); TALEN VA-750B,TALEN VA-780 and TALEN VA-800 (all are products of Kyoeisha Chemical Co,Ltd.); Crayvallac Super (product of CRAY VALLEY); and the like.

The amide wax type thixotropy-imparting agents of the component (C) maybe used either each alone or in combinations of two or more thereof.

The used amount of the component (C) is preferably from 0.1 to 20 partsby weight, and more preferably from 0.5 to 10 parts by weight,especially preferably from 1 to 5 parts by weight with respect to 100parts by weight of the component (A). When the blended amount of thecomponent (C) is less than the above described ranges, sometimes, asufficient effect of improving thixotropy cannot be obtained. On theother hand, when the blended amount of the component (C) exceeds theabove described ranges, there is a tendency that curability is lowered.

A filler can be added to the composition of the present invention.Examples of the fillers include reinforcing fillers such as fumedsilica, precipitated silica, crystalline silica, fused silica, dolomite,anhydrous silicic acid, hydrous silicic acid and carbon black; fillerssuch as ground calcium carbonate, precipitated calcium carbonate,magnesium carbonate, diatomite, sintered clay, clay, talc, titaniumoxide, bentonite, organic bentonite, ferric oxide, aluminum fine powder,flint powder, zinc oxide, active zinc white, shirasu balloon, glassmicroballoon, organic microballoons of phenolic resin and vinylidenechloride resin, and resin powders such as PVC powder and PMMA powder;and fibrous fillers such as asbestos, glass fiber and glass filament.When a filler is used, the used amount thereof is 1 to 250 parts byweight, and preferably 10 to 200 parts by weight with respect to 100parts by weight of the polymer of the component (A).

As described in Japanese Patent Laid-Open No. 2001-181532, it ispossible to homogeneously mix the above described filler with adehydrating agent such as oxidized calcium, put the mixture in a bagmade of an air-tight material to be sealed and then allow to stand for aproper period of time to dehydrate and dry previously. The use of thislow molecular weight filler makes it possible to improve storagestability in the case of one-component type composition.

Additionally, when preparing a highly transparent composition, asdescribed in Japanese Patent Laid-Open No. 11-302527, it is possible touse, as a filler, a polymer powder prepared by using a polymer such asmethyl methacrylate as a starting material or a non-crystalline silica.Also as described in Japanese Patent Laid-Open No. 2000-38560, a highlytransparent composition can be obtained by using, as a filler, ahydrophobic silica which is a fine powder of silicon dioxide havinghydrophobic groups bonded to the surface thereof. The surface of a finepowder of silicon dioxide has generally silanol groups (—SiOH), but canbe formed into a hydrophobic silica by reacting those silanol groupswith halides of organosilicon or alcohols to produce —SiO— hydrophobicgroup. Specifically, the hydrophobic silica is obtained by reactingsilanol groups being present in the surface of the fine powder ofsilicon dioxide with dimethylsiloxane, hexamethyldisilazane,dimethyldichlorosilane, trimethoxyoctylsilane, trimethylsilane or thelike. A fine powder of silicon dioxide in which the surface thereof isformed by silanol groups (—SiOH) is called a hydrophilic fine powder ofsilica.

When it is desired to obtain a cured article high in strength by use ofthese fillers, preferable is a filler mainly selected from fumed silica,precipitated silica, crystalline silica, fused silica, dolomite,anhydrous silicic acid, hydrous silicic acid, carbon black, surfacetreated fine calcium carbonate, sintered clay, clay and active zincwhite; a desirable effect is obtained when such a filler is used withina range from 1 to 200 parts by weight with respect to 100 parts byweight of the reactive silicone group-containing organic polymer (A).Additionally, when it is desired to obtain a cured article low intensile strength and large in elongation at break, a desirable effect isobtained by use of a filler mainly selected from titanium oxide, calciumcarbonate such as ground calcium carbonate and magnesium carbonate,talc, ferric oxide, zinc oxide and shirasu balloon within a range from 5to 200 parts by weight with respect to 100 parts by weight of thereactive silicone group-containing organic polymer (A). It is to benoted that in general, the calcium carbonate exhibits, with increasingspecific surface area value thereof, an increasing improvement effect ofthe tensile strength at break, elongation at break and adhesion of thecured article. Needless to say, these fillers may be used either eachalone or in admixtures of two or more thereof. When calcium carbonate isused, it is desirable to use surface treated fine calcium carbonate incombination with calcium carbonate larger in particle size such asground calcium carbonate. The particle size of surface treated finecalcium carbonate is preferably not more than 0.5 μm, and the surfacetreatment is preferably carried out by treating with a fatty acid or afatty acid salt. The calcium carbonate larger in particle size ispreferably not less than 1 μm in particle size, and can be used withoutbeing subjected to surface treatment.

For the purpose of improving the workability (cutting property, etc) ofthe composition and deglossing the surface of the cured article, organicballoons and inorganic balloons are preferably added. Such fillers canbe subjected to surface treatment, and may be used each alone or can beused in admixtures of two or more thereof. For the purpose of improvingthe workability (cutting property, etc), the particle sizes of theseballoons are preferably not more than 0.1 mm. For the purpose ofdeglossing the surface of the cured article, the particle sizes arepreferably 5 to 300 μm.

On the grounds that the cured article of the composition of the presentinvention is satisfactory in chemical resistance and the like, thecomposition of present invention is suitably used for joints of housingexterior wall such as sizing boards, in particular, ceramic sizingboards, for an adhesive for exterior wall tiles, for an adhesive forexterior wall tiles remaining in the joints and for the like purposes;in this connection, it is desirable that the design of the exterior walland the design of the sealant are in harmony with each other.Particularly, posh exterior walls have come to be used by virtue ofsputter coating and mixing colored aggregates. When the composition ofthe present invention is blended with a scale-like or granulatedmaterial having a diameter of not less than 0.1 mm, preferably of theorder of 0.1 to 5.0 mm, the cured article comes to be in harmony withsuch posh exterior walls, and is excellent in chemical resistance, sothat the composition concerned comes to be an excellent composition inthe sense that the exterior appearance of the cured article remainsunchanged over a long period of time. Use of a granulated materialprovides a dispersed sand-like or sandstone-like surface with a roughtexture, while use of a scale-like material provides an irregularsurface based on the scale-like shape of the material.

The preferable diameter, blended amount and materials for the scale-likeor granulated material are described in Japanese Patent Laid-Open No.9-53063 as follows.

The diameter is not less than 0.1 mm, preferably of the order of 0.1 to5.0 mm, and there is used a material having an appropriate size inconformity with the material quality and pattern of exterior wall.Materials having a diameter of the order of 0.2 mm to 5.0 mm andmaterials having a diameter of the order of 0.5 mm to 5.0 mm can also beused. In the case of a scale-like material, the thickness is set to beas thin as the order of 1/10 to ⅕ the diameter (the order of 0.01 to1.00 mm). The scale-like or granulated material is transported to theconstruction site as a sealant on condition that the material isbeforehand mixed in the main component of the sealant, or is mixed inthe main component of the sealant at the construction site when thesealant is used.

The scale-like or granulated material is blended in a content of theorder of 1 to 200 parts by weight with respect to 100 parts by weight ofa composition such as a sealant composition and an adhesive composition.The blended amount is appropriately selected depending on the size ofthe scale-like or granulated material, and the material quality andpattern of exterior wall.

As the scale-like or granulated material, natural products such assilica sand and mica, synthetic rubbers, synthetic resins and inorganicsubstances such as alumina are used. The material is colored in anappropriate color so as to match the material quality and pattern ofexterior wall to heighten the design quality when filled in the joints.

A preferable finishing method and the like are described in JapanesePatent Laid-Open No. 9-53063.

Additionally, when a balloon (preferably the mean particle size thereofis not less than 0.1 mm) is used for a similar purpose, the surface isformed to have a dispersed sand-like or sandstone-like surface with arough texture, and a reduction of weight can be achieved. The preferablediameter, blended amount and materials for the balloon are described inJapanese Patent Laid-Open No. 10-251618 as follows.

The balloon is a sphere-shaped material with a hollow interior. Examplesof the material for such a balloon include inorganic materials such asglass, shirasu and silica; and organic materials such as phenolic resin,urea resin, polystyrene and Saran™; however, the material concerned isnot limited to these examples; an inorganic material and an organicmaterial can be compounded, or can be laminated to form multiple layers.An inorganic balloon, an organic balloon, a balloon made of a compoundedinorganic-organic material or the like can be used. Additionally, as aballoon to be used, either a type of balloon or an admixture of multipletypes of balloons can be used. Moreover, a balloon with the processedsurface thereof or with the coated surface thereof can be used, andadditionally, a balloon with the surface thereof subjected to treatmentwith various surface treatment agents can also be used. Morespecifically, examples are an organic balloon coated with calciumcarbonate, talc, titanium oxide and the like, and an inorganic balloonsubjected to surface treatment with a silane coupling agent.

For the purpose of obtaining a dispersed sand-like or sandstone-likesurface with a rough texture, the particle size of the balloon ispreferably not less than 0.1 mm. A balloon of a particle size of theorder of 0.2 mm to 5.0 mm or a balloon of a particle size of the orderof 0.5 mm to 5.0 mm can also be used. Use of a balloon of a particlesize of less than 0.1 mm sometimes only increases the viscosity of thecomposition, and yields no rough texture, even when the used amount ofthe balloon is large. The blended amount of the balloon can be easilydetermined in conformity with the desired degree of the dispersedsand-like or sandstone-like rough texture. Usually, it is desirable thata balloon of not less than 0.1 mm in particle size is blended in a ratioof 5 to 25 vol % in terms of the volume concentration in thecomposition. When the volume concentration of the balloon is less than 5vol %, no rough texture can be obtained, while when the volumeconcentration of the balloon exceeds 25 vol %, the viscosity of thesealant and that of the adhesive tend to become high to degrade theworkability, and the modulus of the cured article becomes high, so thatthe basic performance of the sealant and that of the adhesive tend to beimpaired. The preferable volume concentration to balance with the basicperformance of the sealant is 8 to 22 vol %.

When a balloon is used, there can be added an antislip agent describedin Japanese Patent Laid-Open No. 2000-154368 and an amine compound tomake irregular and degloss the surface of the cured article as describedin Japanese Patent Laid-Open No. 2001-164237, in particular, a primaryamine and/or a secondary amine having a melting point of not less than35° C.

Specific examples of the balloon are described in the followingpublications: Japanese Patent Laid-Open Nos. 2-129262, 4-8788, 4-173867,5-1225, 7-113073, 9-53063, 10-251618, 2000-154368 and 2001-164237, andWO97/05201 pamphlet.

Additionally, thermally expandable fine hollow particles disclosed inJapanese Patent Laid-Open No. 2004-51701 or 2004-66749 can be used. Thethermally expandable fine hollow particles are plastic sphericalparticulates produced by surrounding a low boiling point compound suchas a hydrocarbon having 1 to 5 carbon atoms with a high molecular weightshell material (vinylidene chloride copolymer, acrylonitrile copolymeror vinylidene chloride-acrylonitrile copolymer). When the adheredportion obtained by using the composition of the present invention isheated, gas pressure inside the shell of the thermally expandable finehollow particles is increased and the high molecular weight shellmaterial is softened to markedly expand its volume and functions tocause peeling at the adhesion interface. By the addition of thethermally expandable fine hollow particles, it is possible to obtain anadhesive composition which can be peeled easily only by heating withoutbreakage of material when adhesion becomes unnecessary and also can bepeeled by heating without using an organic solvent.

When the composition of the present invention includes the particles ofthe cured article derived from a sealant, the cured article can makeirregularities on the surface to improve the design quality. Thepreferable diameter, blended amount and materials of the cured articleparticle material derived from a sealant is described in Japanese PatentLaid-Open No. 2001-115142 as follows. The diameter is preferably of theorder of 0.1 mm to 1 mm, and further preferably of the order of 0.2 to0.5 mm. The blended amount is preferably 5 to 100 wt %, and furtherpreferably 20 to 50 wt % in the curable composition. Examples of thematerials include urethane resin, silicone, modified silicone andpolysulfide rubber. No constraint is imposed on the materials as long asthe materials can be used as sealants; however, modified siliconesealants are preferable.

To the composition of the present invention can be added anadhesion-imparting agent. No particular constraint is imposed on theadhesion-imparting resins, and usual adhesion-imparting resins can beused irrespective of solid form or liquid form at ordinary temperature.Specific examples of such adhesion-imparting resins include styreneblock copolymers, hydrogenated products thereof, phenolic resins,modified phenolic resins (for example, cashew oil-modified phenolicresins, tall oil-modified phenolic resins and the like), terpenephenolic resins, xylene-phenol resins, cyclopentadiene-phenol resins,cumarone-indene resins, rosin resins, rosin ester resins, hydrogenatedrosin ester resins, xylene resins, low molecular weight polystyreneresins, styrene copolymer resins, petroleum resins (for example, C5hydrocarbon resin, C9 hydrocarbon resin, C5C9 hydrocarbon copolymerresin and the like), hydrogenated petroleum resins, terpene resins, DCPDresin-petroleum resin and the like. Those resins may be used either eachalone or in combinations of two or more thereof. Examples of the styreneblock copolymers and hydrogenated products thereof includestyrene-butadiene-styrene block copolymer (SBS),styrene-isoprene-styrene block copolymer (SIS),styrene-ethylenebutylene-styrene block copolymer (SEBS),styrene-ethylenepropylene-styrene block copolymer (SEPS),styrene-isobutylene-styrene block copolymer (SIBS) and the like. Theabove described adhesion-imparting resins may be used either each aloneor in combinations of two or more thereof.

The adhesion-imparting resins are used within a range from 5 to 1,000parts by weight, preferably from 10 to 100 parts by weight with respectto 100 parts by weight of the organic polymer (A).

A plasticizer can be added to the composition of the present invention.Addition of a plasticizer makes it possible to adjust the viscosity andslump property of the curable composition and the mechanical propertiessuch as tensile strength and elongation of the cured article obtained bycuring the composition. Examples of the plasticizer include phthalatessuch as dibutyl phthalate, diheptyl phthalate, di(2-ethylhexyl)phthalate and butyl benzyl phthalate; non-aromatic dibasic acid esterssuch as dioctyl adipate, dioctyl sebacate, dibutyl sebacate anddiisodecyl succinate; aliphatic esters such as butyl oleate and methylacetyl recinolate; phosphates such as tricresyl phosphate and tributylphosphate; trimellitates; chlorinated paraffins; hydrocarbon oils suchas alkyldiphenyls and partially hydrogenated terphenyls; process oils;epoxy plasticizers such as epoxidized soybean oil and benzylepoxystearate.

Additionally, a polymer plasticizer can be used. When a polymerplasticizer is used, initial physical properties are maintained for along period of time as compared with the case of using a low molecularweight plasticizer containing no polymer component in the molecule.Further, drying property (also referred to as coating property) in thecase of coating of an alkyd coating material on the cured article can beimproved. Examples of the polymer plasticizer include vinyl polymersobtained by polymerizing vinyl monomers by means of various methods;polyalkylene glycol esters such as diethylene glycol dibenzoate,triethylene glycol dibenzoate and pentaerythritol ester; polyesterplasticizers obtained from dibasic acids such as sebacic acid, adipicacid, azelaic acid and phthalic acid and dihydric alcohols such asethylene glycol, diethylene glycol, triethylene glycol, propylene glycoland dipropylene glycol; polyethers including polyether polyols eachhaving a molecular weight of not less than 500, additionally not lessthan 1,000 such as polyethylene glycol, polyprolpylene glycol andpolytetramethylene glycol, and the derivatives of these polyetherpolyols in which the hydroxy groups in these polyether polyols aresubstituted with ester groups, ether groups and the like; polystyrenessuch as polystyrene and poly-α-methylstyrene; and polybutadiene,polybutene, polyisobutylene, butadiene-acrylonitrile andpolychloroprene. However, the polymer plasticizer concerned is notlimited to these examples.

Of these polymer plasticizers, the polymer plasticizers which arecompatible with the polymer of component (A) are preferable. In thisregard, polyethers and vinyl polymers are preferable. Additionally, whenpolyethers are used as plasticizers, the surface curability anddeep-part curability are improved, and no curing retardation afterstorage occurs, and hence polyethers are preferable; of polyethers,polypropylene glycol is more preferable. Additionally, from theviewpoint of the compatibility, weather resistance and heat resistance,vinyl polymers are preferable. Of the vinyl polymers, acryl polymersand/or methacryl polymers are preferable, and acryl polymers such aspolyalkylacrylate are further preferable. As the polymerization methodto produce acryl polymers, the living radical polymerization method ispreferable because this method can lead to narrow molecular weightdistributions and low viscosities, and the atom transfer radicalpolymerization method is further preferable. Additionally, it ispreferable to use a polymer based on the so-called SGO process which isobtained by continuously block-polymerizing an alkyl acrylate monomer ata high temperature under a high pressure, as described in JapanesePatent Laid-Open No. 2001-207157.

The number average molecular weight of the polymer plasticizer ispreferably 500 to 15,000, more preferably 800 to 10,000, furtherpreferably 1,000 to 8,000, particularly preferably 1,000 to 5,000, andmost preferably 1,000 to 3,000. When the molecular weight is too low,the plasticizer is removed with time due to heat and by rainfall, andhence it is made impossible to maintain the initial physical propertiesover a long period of time, and the coating property with an alkydcoating material cannot be improved. On the other hand, when themolecular weight is too high, the viscosity becomes high and theworkability is degraded. No particular constraint is imposed on themolecular weight distribution of the polymer plasticizer. However, it ispreferable that the molecular weight distribution is narrow; themolecular weight distribution is preferably less than 1.80, morepreferably not more than 1.70, further preferably not more than 1.60,yet further preferably not more than 1.50, particularly preferably notmore than 1.40 and most preferably not more than 1.30.

The number average molecular weight of a vinyl polymer is measured withthe GPC method, and that of a polyether polymer is measured with theterminal group analysis method. Additionally, the molecular weightdistribution (Mw/Mn) is measured with the GPC method (relative topolystyrene standard).

Additionally, the polymer plasticizer either may have no reactivesilicon group or may have a reactive silicon group. When the polymerplasticizer has a reactive silicon group, the polymer plasticizer actsas a reactive plasticizer, and can prevent the migration of theplasticizer from the cured article. When the polymer plasticizer has areactive silicon group, the average number of reactive silicon groupsper molecule is not more than 1, and preferably not more than 0.8. Whenthe reactive silicon group-containing plasticizer, in particular, areactive silicon group-containing oxyalkylene polymer is used, it isnecessary that the number average molecular weight thereof is lower thanthat of the organic polymer (A).

The plasticizers may be used either each alone or in combinations of twoor more thereof. Additionally, a low molecular weight plasticizer and apolymer plasticizer may be used in combination. It is to be noted thatthese plasticizers can also be blended when the polymer is produced.

The used amount of the plasticizer is 5 to 150 parts by weight,preferably 10 to 120 parts by weight, and further preferably 20 to 100parts by weight, with respect to 100 parts by weight of the polymer ofthe component (A). When the used amount is less than 5 parts by weight,the effect as the plasticizer is not exhibited, while when the usedamount exceeds 150 parts by weight, the mechanical strength of the curedarticle is insufficient.

To the curable composition of the present invention may be added, ascase demands, a compound to hydrolytically produce a compound having amonovalent silanol group in the molecule thereof. This compound has aneffect of decreasing the modulus of the cured article without degradingthe stickiness of the surface of the cured article. Particularly, acompound to produce trimethylsilanol is preferable. Examples of thecompound to hydrolytically produce a compound having a monovalentsilanol group in the molecule thereof include a compound described inJapanese Patent Laid-Open No. 5-117521. Additionally, examples of such acompound include a compound which is a derivative of an alkyl alcoholsuch as hexanol, octanol or decanol, and produces a silicon compound tohydrolytically produce R₃SiOH such as trimethylsilanol, and a compounddescribed in Japanese Patent Laid-Open No. 11-241029 which is aderivative of a polyhydric alcohol having three or more hydroxy groupssuch as trimethylolpropane, glycerin, pentaerythritol or sorbitol, andproduces a silicon compound to hydrolytically produce R₃SiOH such astrimethylsilanol.

Additionally, there can be cited such a compound as described inJapanese Patent Laid-Open No. 7-258534 which is a derivative ofoxypropylene polymer and produces a silicon compound to hydrolyticallyproduce R₃SiOH such as trimethylsilanol. Moreover, there can be used apolymer described in Japanese Patent Laid-Open No. 6-279693 whichcontains a hydrolyzable silicon-containing group capable ofcross-linking and a silicon-containing group capable of hydrolyticallyforming a monosilanol-containing compound.

The compound to hydrolytically produce a compound having a monovalentsilanol group in the molecule thereof is used within a range from 0.1 to20 parts by weight, and preferably from 0.5 to 10 parts by weight, withrespect to 100 parts by weight of the reactive silicon group-containingorganic polymer (A).

In the composition of the present invention, a compound containing anepoxy group in one molecule can be used. Use of an epoxygroup-containing compound can increase the recovery properties of thecured article. Examples of the epoxy group-containing compound includecompounds such as epoxidized unsaturated oils and fats, epoxidizedunsaturated fatty acid esters, alicyclic epoxy compounds andepichlorohydrin derivatives, and admixtures of these compounds. Morespecific examples include epoxidized soybean oil, epoxidized flaxseedoil, bis(2-ethylhexyl)-4,5-epoxycyclohexane-1,2-dicarboxylate (E-PS),epoxyoctyl stearate and epoxybutyl stearate. Of these, E-PS isparticularly preferable. It is recommended that these epoxygroup-containing compounds each are used within a range from 0.5 to 50parts by weight with respect to 100 parts by weight of the reactivesilicon group-containing organic polymer (A).

For the composition of the present invention, a photocuring substancecan be used. Use of a photocuring substance forms a coating film of thephotocuring substance on the surface of the cured article to improve thestickiness and the weather resistance of the cured article. Aphotocuring substance means a substance which undergoes a chemicalchange, caused by action of light, of the molecular structure thereof ina fairly short time to result in changes of the physical properties suchas curability. Among such a large number of compounds known are organicmonomers, oligomers, resins and compositions containing thesesubstances, and any commercially available substances concerned canoptionally be adopted. As representative photocuring substances,unsaturated acryl compounds, polyvinyl cinnamates, azidized resins andthe like can be used. The unsaturated acryl compounds are monomers,oligomers and admixtures of the monomers and the oligomers, the monomersand oligomers each having one or a few acryl or methacryl unsaturatedgroups; examples of the unsaturated acryl compounds include monomerssuch as propylene (or butylene, or ethylene)glycol di(meth)acrylate andneopentylglycol di(meth)acrylate, and oligoesters of not more than10,000 in molecular weight related to these monomers. Specific examplesinclude special acrylates (bifunctional) such as ARONIX M-210, ARONIXM-215, ARONIX M-220, ARONIX M-233, ARONIX M-240 and ARONIX M-245;special acrylates (trifunctional) such as ARONIX M-305, ARONIX M-309,ARONIX M-310, ARONIX M-315, ARONIX M-320 and ARONIX M-325; and specialacrylates (multifunctional) such as ARONIX M-400. Those compounds whicheach have acrylic functional groups are particularly preferable, andadditionally, those compounds which each have, on average, three or moreacrylic functional groups in one molecule are preferable (all theaforementioned ARONIXs are the products of Toagosei Co., Ltd.).

Examples of the polyvinyl cinnamates include photosensitive resinshaving cinnamoyl groups as photosensitive groups, namely, thosecompounds obtained by esterification of polyvinyl alcohol with cinnamicacid; and additionally, a large number of derivatives of polyvinylcinnamates. Azidized resins are known as photosensitive resins havingazide groups as photosensitive groups; common examples of the azidizedresins include a rubber photosensitive solution added with an azidecompound as a photosensitive agent, and additionally, the compoundsdetailed in “photosensitive resins” (published by Insatu GakkaiShuppanbu, Mar. 17, 1972, p. 93, p. 106 and p. 117); and these compoundscan be used each alone or in admixtures thereof, and in combination withsensitizers to be added according to need. It is to be noted thataddition of sensitizers such as ketones and nitro compounds andaccelerators such as amines sometimes enhances the effect. It isrecommended that the photocuring substance is used within a range from0.1 to 20 parts by weight and preferably from 0.5 to 10 parts by weightwith respect to 100 parts by weight of the reactive silicongroup-containing organic polymer (A); when the content of thephotocuring substance is less than 0.1 part by weight, no effect toincrease the weather resistance is displayed, while when the contentexceeds 20 parts by weight, the cured article tends to be too hard andcracked.

For the composition of the present invention, an oxygen-curablesubstance can be used. Examples of the oxygen-curable substance includeunsaturated compounds reactable with the oxygen in the air, which reactwith the oxygen in the air and form a cured coating film around thesurface of the cured article to act to prevent the surface stickinessand the sticking of dust and grime to the surface of the cured articleand to do the like. Specific examples of the oxygen-curable substanceinclude drying oils represented by wood oil, flaxseed oil and the likeand various alkyd resins obtained by modifying these compounds; acrylpolymers, epoxy resins and silicon resins all modified with drying oils;liquid polymers such as 1,2-polybutadiene and 1,4-polybutadiene obtainedby polymerizing or copolymerizing diene compounds such as butadiene,chloroprene, isoprene and 1,3-pentadiene, and polymers derived from C5to C8 dienes, liquid copolymers such as NBR, SBR and the like obtainedby copolymerizing these diene compounds with monomers such asacrylonitrile, styrene and the like having copolymerizability so as forthe diene compounds to dominate, and various modified substances ofthese compounds (maleinized modified substances, boiled oil-modifiedsubstances, and the like). These substances can be used either eachalone or in combinations of two or more thereof. Of these substances,wood oil and liquid diene polymers are particularly preferable.Additionally, in some cases, when catalysts to accelerate the oxidationcuring reaction and metal dryers are used in combination with thesesubstances, the effect is enhanced. Examples of these catalysts andmetal dryers include metal salts such as cobalt naphthenate, leadnaphthenate, zirconium naphthenate, cobalt octylate and zirconiumoctylate; and amine compounds. It is recommended that the oxygen-curingsubstance is used within a range from 0.1 to 20 parts by weight andfurther preferably from 0.5 to 10 parts by weight with respect to 100parts by weight of the reactive silicon group-containing organic polymer(A); when the used amount is less than 0.1 part by weight, improvementof stain-proof property becomes insufficient, while when the used amountexceeds 20 parts by weight, the tensile property and the like of thecured article tends to be impaired. It is recommended that theoxygen-curing substance is used in combination with a photocuringsubstance as described in Japanese Patent Laid-Open No. 3-160053.

For the composition of the present invention, an antioxidant (antiagingagent) can be used. Use of an antioxidant can increase the heatresistance of the cured article. Examples of the antioxidant can includehindered phenol antioxidants, monophenol antioxidants, bisphenolantioxidants and polyphenol antioxidants, and hindered phenolantioxidants are particularly preferable. Similarly, the followinghindered amine photostabilizers can also be used: TINUVIN 622LD, TINUVIN144; CHIMASSORB944LD and CHIMASSORB119FL (all produced by Ciba-GeigyJapan Ltd.); MARK LA-57, MARK LA-62, MARK LA-67, MARK LA-63 and MARKLA-68 (all produced by Adeka Corporation); and SANOL LS-770, SANOLLS-765, SANOL LS-292, SANOL LS-2626, SANOL LS-1114 and SANOL LS-744 (allproduced by Sankyo Co., Ltd.). Specific examples of the antioxidants aredescribed also in Japanese Patent Laid-Open Nos. 4-283259 and 9-194731.It is recommended that the antioxidant is used within a range from 0.1to 10 parts by weight and further preferably from 0.2 to 5 parts byweight with respect to 100 parts by weight of the reactive silicongroup-containing organic polymer (A).

For the composition of the present invention, a photostabilizer can beused. Use of a photostabilizer can prevent the photooxidationdegradation of the cured article. Examples of the photostabilizerinclude benzotriazole compounds, hindered amine compounds, benzoatecompounds and the like; hindered amine compounds are particularlypreferable. It is recommended that the photostabilizer is used within arange from 0.1 to 10 parts by weight and further preferably from 0.2 to5 parts by weight with respect to 100 parts by weight of the reactivesilicon group-containing organic polymer (A). Specific examples of thephotostabilizer are described in Japanese Patent Laid-Open No. 9-194731.

When the photocuring substance is used for the composition of thepresent invention, in particular, when an unsaturated acryl compound isused, it is preferable to use a tertiary amine-containing hindered aminephotostabilizer as a hindered amine photostabilizer as described inJapanese Patent Laid-Open No. 5-70531 for the purpose of improving thestorage stability of the composition. Examples of the tertiaryamine-containing hindered amine photostabilizer include TINUVIN 622LD,TINUVIN 144 and CHIMASSORB119FL (all produced by Ciba-Geigy Japan Ltd.);MARK LA-57, LA-62, LA-67 and LA-63 (all produced by Adeka Corporation);and SANOL LS-765, SANOL LS-292, SANOL LS-2626, SANOL LS-1114 and SANOLLS-744 (all produced by Sankyo Co., Ltd.).

For the composition of the present invention, an ultraviolet absorbercan be used. Use of an ultraviolet absorber can increase the surfaceweather resistance of the cured article. Examples of the ultravioletabsorber include benzophenone compounds, benzotriazole compounds,salicylate compounds, substituted tolyl compounds and metal chelatecompounds; benzotriazole compounds are particularly preferable. Theultraviolet absorber is used within a range from 0.1 to 10 parts byweight, and further preferably from 0.2 to 5 parts by weight withrespect to 100 parts by weight of the reactive silicon group-containingorganic polymer (A). It is preferable that a phenol antioxidant, ahindered phenol antioxidant, a hindered amine photostabilizer and abenzotriazole ultraviolet absorber are used in combination.

To the composition of the present invention, an epoxy resin can beadded. The composition added with an epoxy resin is particularlypreferable as an adhesive, in particular, an adhesive for exterior walltile. Examples of the epoxy resin include epichlorohydrin-bisphenolA-type epoxy resins, epichlorohydrin-bisphenol F-type epoxy resins,flame resistant epoxy resins such as glycidyl ether oftetrabromobisphenol A, novolac-type epoxy resins, hydrogenated bisphenolA-type epoxy resins, epoxy resins of the type of glycidyl ether ofbisphenol A propyleneoxide adduct, p-oxybenzoic acid glycidyl etherester-type epoxy resins, m-aminophenol epoxy resins,diaminodiphenylmethane epoxy resins, urethane modified epoxy resins,various alicyclic epoxy resins, N,N-diglycidylaniline,N,N-diglycidyl-o-toluidine, triglycidyl isocyanurate, polyalkyleneglycol diglycidyl ether, glycidyl ethers of polyhydric alcohols such asglycerin, hydantoin-type epoxy resins and epoxidized substances ofunsaturated polymers such as petroleum resins; however the epoxy resinis not limited to these examples, and commonly used epoxy resins can beused. Epoxy resins having at least two epoxy groups in one molecule arepreferable because such compositions are high in reactivity when curingis made, and the cured articles can easily form three dimensionalnetworks. Examples of further preferable epoxy resins include bisphenolA-type epoxy resins or novolac-type epoxy resins. The ratio of the usedamount of each of these epoxy resins to the used amount of the reactivesilicon group-containing organic polymer (A) falls, in terms of weightratio, in the range such that organic polymer (A)/epoxy resin=100/1 to1/100. When the ratio of organic polymer (A)/epoxy resin is less than1/100, the effect of improving the impact strength and the toughness ofthe cured article of the epoxy resin becomes hardly obtainable, whilewhen the ratio of organic polymer (A)/epoxy resin exceeds 100/1, thestrength of the cured article of the organic based polymer becomesinsufficient. The preferable ratio of the used amounts varies dependingon the application of the curable resin composition and hence cannot beunconditionally determined; for example, when the impact resistance,flexibility, toughness, peel strength and the like of the cured articleof the epoxy resin are to be improved, it is recommended that withrespect to 100 parts by weight of the epoxy resin, 1 to 100 parts byweight of the component (A), further preferably 5 to 100 parts by weightof the component (A) is used. On the other hand, when the strength ofthe cured article of the component (A) is to be improved, it isrecommended that with respect to 100 parts of the component (A), 1 to200 parts by weight of the epoxy resin, further preferably 5 to 100parts by weight of the epoxy resin is used.

When the epoxy resin is added, as a matter of course, a curing agent tocure the epoxy resin can be applied together to the composition of thepresent invention. No particular constraint is imposed on the usableepoxy resin-curing agent, and commonly used epoxy resin-curing agentscan be used. Specific examples of the epoxy resin-curing agent includeprimary and secondary amines such as triethylenetetramine,tetraethylenepentamine, diethylaminopropylamine, N-aminoethylpiperidine,m-xylylenediamine, m-phenylenediamine, diaminodiphenylmethane,diaminodiphenylsulfone, isophoronediamine, and polyether with amineterminal groups; tertiary amines such as2,4,6-tris(dimethylaminomethyl)phenol and tripropylamine, and salts ofthose tertiary amines; polyamide resins; imidazoles; dicyandiamides;borontrifluoride complexes; carboxylic anhydrides such as phthalicanhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride,dodecynylsuccinic anhydride, pyromellitic anhydride and chlorendicanhydride; alcohols; phenols; carboxylic acids; and diketone complexesof aluminum and zirconium. However, the epoxy resin-curing agent is notlimited to these examples. Additionally, the curing agents may be usedeither each alone or in combinations of two or more thereof.

When an epoxy resin-curing agent is used, the used amount thereof fallswithin a range from 0.1 to 300 parts by weight with respect to 100 partsby weight of the epoxy resin.

As an epoxy resin-curing agent, a ketimine can be used. A ketimine isstable when no moisture is present, but moisture decomposes the ketimineinto a primary amine and a ketone; the thus produced primary amine actsas a room temperature curable curing agent to cure the epoxy resin. Useof a ketimine makes it possible to obtain a one-component typecomposition. Such a ketimine can be obtained by condensation reaction ofan amine compound and a carbonyl compound.

For the synthesis of a ketimine, an amine compound and a carbonylcompound well known in the art can be used. For example, the followingcompounds can be used as such an amine compound: diamines such asethylenediamine, propylenediamine, trimethylenediamine,tetramethylenediamine, 1,3-diaminobutane, 2,3-diaminobutane,pentamethylenediamine, 2,4-diaminopentane, hexamethylenediamine,p-phenylenediamine and p,p′-biphenylenediamine; polyvalent amines suchas 1,2,3-triaminopropane, triaminobenzene, tris(2-amionoethyl)amine andtetrakis(aminomethyl)methane; polyalkylenepolyamines such asdiethylenetriamine, triethylenetriamine and tetraethylenepentamine;polyoxyalkylene polyamines; and aminosilanes such asγ-aminopropyltriethoxysilane,N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane andN-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane. Additionally, thefollowing compounds can be used as such a carbonyl compound: aldehydessuch as acetaldehyde, propionaldehyde, n-butylaldehyde,isobutylaldehyde, diethylacetaldehyde, glyoxal and benzaldehyde; cyclicketones such as cyclopentanone, trimethylcyclopentanone, cyclohexanoneand trimethylcyclohexanone; aliphatic ketones such as acetone, methylethyl ketone, methyl propyl ketone, methyl isopropyl ketone, methylisobutyl ketone, diethyl ketone, dipropyl ketone, diisopropyl ketone,dibutyl ketone and diisobutyl ketone; and β-dicarbonyl compounds such asacetylacetone, methyl acetoacetate, ethyl acetoacetate, dimethylmalonate, diethyl malonate, methyl ethyl malonate and dibenzoylmethane.

When an imino group is present in the ketimine, the imino group can bereacted with styrene oxide; glycidyl ethers such as butyl glycidyl etherand allyl glycidyl ether; and glycidyl esters. These ketimines may beused either each alone or in combinations of two or more thereof; theseketimines each are used within a range from 1 to 100 parts by weightwith respect to 100 parts by weight of the epoxy resin, the used amountof each of the ketimines varies depending on the type of the epoxy resinand the type of the ketimine.

To the curable composition of the present invention can be added aphosphorous-based plasticizer such as polyphosphoric acid ammonium ortricresyl phosphate and a flame retardant such as aluminum hydroxide,magnesium hydroxide or thermally expandable graphite. These flameretardants may be used either each alone or in combinations of two ormore thereof.

The flame retardant is used within a range from 5 to 200 parts by mass,and preferably from 10 to 100 parts by mass with respect to 100 parts byweight of the component (A).

To the composition of the present invention can be added a solvent forthe purposes of decreasing a viscosity, enhancing thixotropy andimproving workability. No particular constraint is imposed on thesolvent, and various compounds can be used. Specific examples thereofinclude hydrocarbon solvents such as toluene, xylene, heptane, hexaneand petroleum solvents; halogen solvents such as trichloroethylene;ester solvents such as ethyl acetate and butyl acetate; ketone solventssuch as acetone, methyl ethyl ketone and methyl isobutyl ketone; ethersolvents; alcohol solvents such as methanol, ethanol and isopropanol;and silicone solvents such as hexamethylcyclotrisiloxane,octamethylcyclotetrasiloxane and decamethylcyclopentasiloxane. When asolvent is used, the boiling point of the solvent is preferably not lessthan 150° C., more preferably not less than 200° C., particularlypreferably not less than 250° C. from the viewpoint of a problem withcontamination to the air when the composition is used indoor. Thesesolvents may be used either each alone or in combinations of two or morethereof.

It is to be noted that when the blended amount of the solvents isabundant, in some cases, toxicity to human body becomes high, and avolume shrinkage of the cured article occurs. Accordingly, the blendedamount of the solvents is preferably not more than 3 parts by weight,more preferably not more than 1 part by weight with respect to 100 partsby weight of the organic polymer of the component (A), and it is mostpreferable that no solvents are contained substantially in thecomposition.

To the curable composition of the present invention, various additivescan be added according to need for the purpose of regulating thephysical properties of the curable composition or the cured article.Examples of such additives include curing regulators, radicalinhibitors, metal deactivators, antiozonants, phosphorus-based peroxidedecomposers, lubricants, pigments, foaming agents, ant-proofing agentsand mildewproofing agents. These various additives may be used eithereach alone or in combinations of two or more thereof. Specific examplesof additives other than the specific examples cited in the presentspecification are described, for example, in Japanese Patent ExaminedPublication Nos. 4-69659 and 7-108928, Japanese Patent Laid-Open Nos.63-254149, 64-22904, 2001-72854 and the like.

The curable composition of the present invention can also be prepared asa one-component type composition curable after application with moisturein the air in such a way that all the blended components are beforehandblended together and hermetically stored. The curable composition of thepresent invention can also be prepared as two-component type compositionin such a way that a compound agent is prepared as a curing agent byblending together a curing catalyst, a filler, a plasticizer and water,and the thus blended material is mixed with a polymer composition beforeuse. From the viewpoint of workability, a one-component type compositionis preferable.

When the above described curable composition is of the one-componenttype, all the blended components are blended together beforehand, sothat it is preferable that the blended components containing moistureare used after dehydrating and drying, or the components are dehydratedby reducing pressure or the like while being kneaded for blending. Whenthe above described curable composition is of the two-component type, itis not necessary to blend a curing catalyst with the main componentcontaining a reactive silicon group-containing polymer, and hence thereis little fear of gelation even when some moisture is contained in theblended components; however, when a long term storage stability isrequired, it is preferable to carry out dehydration and drying. As forthe methods of dehydration and drying, a thermal drying method issuitable for a powdery solid substance or the like, while a reducedpressure dehydration method or a dehydration method which uses asynthetic zeolite, active alumina, silica gel, quick lime or magnesiumoxide is suitable for a liquid substance. Additionally, there can beadopted a method in which a small amount of an isocyanate compound isadded to make its isocyanate group react with water for dehydration, ora method in which an oxazolidine compound such as3-ethyl-2-methyl-2-(3-methylbutyl)-1,3-oxazolidine is added to make itreact with water for dehydration. In addition to these dehydration anddrying methods, addition of the following compounds further improves thestorage stability: lower alcohols such as methanol and ethanol; andalkoxysilane compounds such as n-propyltrimethoxysilane,vinyltrimethoxysilane, vinylmethyldimethoxysilane, methylsilicate,ethylsilicate, γ-mercaptopropylmethyldimethoxysilane,γ-mercaptopropylmethyldiethoxysilane andγ-glycidoxypropyltrimethoxysilane.

It is particularly preferable that the used amount of a dehydratingagent, in particular, a silicon compound capable of reacting with watersuch as vinyltrimethoxysilane falls within a range from 0.1 to 20 partsby weight, and preferably 0.5 to 10 parts by weight with respect to 100parts by weight of the reactive silicon group-containing organic polymer(A).

No particular constraint is imposed on the preparation method of thecurable composition of the present invention; for example, there can beadopted a common method in which the above described components areblended together and kneaded with a mixer, a roll or a kneader at roomtemperature or under heating, or a common method in which the abovedescribed components are dissolved and mixed by use of a small amount ofan appropriate solvent.

The curable composition of the present invention forms three dimensionalnetworks when exposed to the air due to the action of the moisture to becured into a solid matter having a rubber-like elasticity.

The curable composition of the present invention can be used astackifiers, sealants for buildings, ships, vehicles and road, adhesives,mold forming materials, vibration-proof material, damping materials,soundproof materials, foaming materials, coating materials, sprayingmaterials and the like. It is preferable that the cured article obtainedby curing the curable composition of the present invention is used as asealant and an adhesive because the cured article is excellent inflexibility and adhesion.

Additionally, the curable composition of the present invention can beused in various applications as liquid sealants to be used in materialsfor electric and electronic components such as backside sealants forsolar cells, electric insulating materials such as insulating coatingmaterials for use in electric wire and cable, elastic adhesives, contacttype adhesives, spray type sealants, crack repairing materials,adhesives for tiling, powdery coating materials, casting materials,medical rubber materials, medical adhesives, medical instrumentsealants, food packaging materials, sealants for joints in exteriormaterials such as sizing boards, coating materials, primers,electromagnetic wave shielding conductive materials, heat conductingmaterials, hot melt materials, electric and electronic potting agents,films, gaskets, various molding materials, antirust and waterproofsealants for edges (cut portions) of wire glass and laminated glass,vehicle components, electric appliance components, various machinerycomponents and the like. Moreover, the curable composition of thepresent invention can adhere alone or in combination with a primer to awide variety of substrates including glass, porcelain, woods, metals andmolded resin articles, and accordingly, can be used as various types ofsealing and adhesive compositions. Additionally, the curable compositionof the present invention can be used as adhesives for interior panels,adhesive for exterior panels, adhesives for tiling, adhesives for stonetiling, adhesives for finishing ceiling, adhesives for finishing floor,adhesives for finishing wall, adhesives for vehicle panels, adhesivesfor assembling electric, electronic and precision instruments, sealantsfor direct glazing, sealants for double glazing, sealants for the SSGtechnique and sealants for working joints of buildings.

EXAMPLES

In the next place, the present invention is specifically described onthe basis of examples and comparative examples, but the presentinvention is not limited by these examples and comparative examples.

Synthesis Example 1

By use of a polyoxypropylene glycol having a molecular weight of about2,000 as an initiator and zinc hexacyanocobaltate-glyme complex as acatalyst, polymerization of propylene oxide was carried out to yield ahydroxy group-terminated polypropylene oxide having a number averagemolecular weight of about 25,500 (a molecular weight relative topolystyrene standard measured by using a HLC-8120 GPC manufactured byTosoh Corp. as a liquid delivery system, a column of TSK-GEL H-typemanufactured by Tosoh Corp., and THF as a solvent). Then, a methanolsolution of NaOMe was added in an amount of 1.2 equivalents with respectto the hydroxy group of the above hydroxy group-terminated polypropyleneoxide, the methanol was distilled off, and allyl chloride was furtheradded to thereby convert the terminal hydroxy group into an allyl group.The unreacted allyl chloride was distilled off under reduced pressure.To 100 parts by weight of the obtained crude allyl-terminatedpolypropylene oxide, 300 parts by weight of n-hexane and 300 parts byweight of water were added. The mixture thus obtained was stirred tomix, and then the water was removed by centrifugal separation. To thehexane solution thus obtained, 300 parts by weight of water was furtheradded, the mixture thus obtained was stirred to mix, the water was againremoved by centrifugal separation, and then the hexane was distilled offunder reduced pressure. Thus, an allyl group-terminated bifunctionalpolypropylene oxide having a number average molecular weight of about25,500 was obtained.

100 Parts by weight of the obtained allyl group-terminated polypropyleneoxide and 0.9 part by weight of methyldimethoxysilane were reacted at90° C. for five hours by using, as a catalyst, 150 ppm of isopropanolsolution of platinum-vinylsiloxane complex containing 3 wt % platinum toyield a polyoxypropylene polymer (A-1) terminated withmethyldimethoxysilyl group. By measurement using ¹H-NMR (measured inCDCl₃ as a solvent by use of a JNM-LA400 manufactured by JEOL Ltd.), thenumber of terminal methyldimethoxysilyl groups per molecule was 1.3 onaverage.

Synthesis Example 2

An allyl group-terminated polypropylene oxide was obtained in the samemanner as in Synthesis Example 1 by using a hydroxyl group-terminatedpolypropylene oxide having a number average molecular weight of about19,000 and obtained by polymerizing propylene oxide by use of a 1/1(weight ratio) mixture of a polyoxypropylene diol having a molecularweight of about 2,000 and a polyoxypropylene triol having a molecularweight of about 3,000 as an initiator and zinc hexacyanocobaltate-glymecomplex as a catalyst. This allyl group-terminated polypropylene oxidewas reacted with 1.35 parts by weight of methyldimethoxysilane in thesame manner as in Synthesis Example 1 to yield a polyoxypropylenepolymer (A-2) having 1.7 terminal methyldimethoxysilyl groups onaverage.

Synthesis Example 3

To a 2-butanol solution of the following monomer mixture heated to 105°C. was added dropwise over five hours a solution prepared by dissolving2,2′-azobis(2-methylbutyronitrile) as a polymerization initiator,followed by one-hour “post-polymerization” to yield a (meth)acrylatepolymer (A-3).

46.8 parts by weight of methyl methacrylate, 28.6 parts by weight ofbutyl acrylate, 20.1 parts by weight of stearyl methacrylate, 4.5 partsby weight of γ-methacryloxypropyldimethoxymethylsilane, 2.7 parts byweight of 2,2′-azobis(2-methylbutyronitrile)

Synthesis Example 4

After mixing the polymer (A-2) obtained in Synthesis Example 2 and thepolymer (A-3) obtained in Synthesis Example 3 at 80/20 in a weight ratioof solid contents, a solvent was distilled off to yield a solvent-freepolymer (A-4).

Examples 1 to 3 and Comparative Examples 1 to 4

100 Parts by weight of the reactive silicon group-containing organicpolymer (A-1, A-4) obtained in Synthesis Example 1 or 4, 120 parts byweight of a surface-treated colloidal calcium carbonate (Hakuenka CCRproduced by Shiraishi Kogyo Kaisha, Ltd.), 20 parts by weight of atitanium oxide (Tipaque R-820 produced by Ishihara Sangyo Kaisha, Ltd.),55 parts by weight of a plasticizer: diisodecyl phthalate (SANSOClZERDIDP produced by New Japan Chemical Co., Ltd.), an amide wax typethixotropy-imparting agent (Disparlon 6500 produced by KusumotoChemicals, Ltd.) or a hydrogenated castor oil type thixotropy-impartingagent (Disparlon 305 produced by Kusumoto Chemicals, Ltd.) in a part byweight shown in Table 1, 1 part by weight of a photostabilizer (SanolLS765 produced by Sankyo Co., Ltd.), 1 part by weight of an ultravioletabsorber (Sumisorb 400 produced by Sumitomo Chemical Co., Ltd.), 1 partby weight of an antioxidant (Irganox 1010 produced by Ciba-Geigy JapanLtd.), 2 parts by weight of vinyltrimethoxysilane (A-171 produced byToray Dow Corning Co., Ltd.), 3 parts by weight ofN-(β-aminoethyl)-γ-aminopropyltrimethoxysilane (A-1120 produced by TorayDow Corning Co., Ltd.), and 7.5 parts by weight of titaniumdiisopropoxidebis(ethylacetoacetate) (Orgatix TC-750 of MatsumotoTrading Co., Ltd.) as a curing catalyst of the component (B), 5 parts byweight of titanium tetraisopropoxide (produced by Wako Pure ChemicalsCo., Ltd.) as a titanium catalyst other than the component (B) or 1 partby weight of dibutyltin bis(acetylacetonate) (Neostann U-220 produced byNitto Kasei Kaisha Ltd. as an organotin catalyst were added according tothe formulations shown in Table 1. Then the mixture was kneaded underdehydrating condition in a state substantially free from moisture andsealed in a moisture-proof vessel to yield one-component type curablecompositions. (The added parts by weight of the titanium catalyst wasadjusted so that the number of moles of titanium atoms in thecompositions was the same)

The curable compositions each were extruded from the cartridge andfilled in a molding frame of about 5 mm in thickness with a spatula; thesurface of each of the filled compositions was fully flattened, and theplanarization completion time was set as the curing starting time. Thesurface of each of the compositions was touched with a spatula, and theskin formation time was measured as the time when the composition nolonger stuck to the spatula. The skin formation time was measured at 23°C. at 50% RH.

A viscosity of each one-component type curable composition was measuredat 23° C. at a rotation speed of 1 rpm, 2 rpm and 10 rpm with a BS typeviscometer (manufactured by Tokyo Keiki Co., Ltd., No. 7 rotor).Thixotropy of the compositions was evaluated by a ratio of viscositiesat 2 rpm and 10 rpm. Further, application of composition was conductedusing a spatula, and workability was evaluated by a degree of cobwebbingunder the following criteria

A: Cobwebbing is small and finishing with a spatula is easy.

B: Cobwebbing is large and finishing with a spatula is difficult.

Components of the composition, and the results of evaluation of skinformation time, viscosity and workability are shown in Table 1. TABLE 1Example Compositions (part by weight) 1 2 3 Organic polymer A-1 100 100A-4 100 Filler Hakuenka CCR 120 120 120 Taipaque R-820 20 20 20Plasticizer SANSOCIZER DIDP 55 55 55 Amide wax Disparlon #6500 2 2 6Hydrogenated castor oil Disparlon #305 Ultraviolet absorber Sumisorb 4001 1 1 Photostabilizer Sanol LS-765 1 1 1 Antioxidant Irganox 1010 1 1 1Dehydrating agent A-171 2 2 2 Adhesion-imparting agent A-1120 3 3 3Titanium diisopropoxidebis(ethylacetoacetate) TC-750 7.5 7.5 7.5Titanium tetraisopropoxide Dibutyltinbis(acetylacetonate) U-220 Skinformation time (min) 150 120 225 Viscosity (Pa · s) 1 rpm 1,580 1,5502,390 2 rpm 940 840 1,490 10 rpm 300 270 410 Viscosity ratio 3.1 3.1 3.6(2 rpm/10 rpm) Workability A A A Comparative Example Compositions (partby weight) 1 2 3 4 Organic polymer A-1 100 100 100 100 A-4 FillerHakuenka CCR 120 120 120 120 Taipaque R-820 20 20 20 20 PlasticizerSANSOCIZER DIDP 55 55 55 55 Amide wax Disparlon #6500 2 2 Hydrogenatedcastor oil Disparlon #305 2 2 Ultraviolet absorber Sumisorb 400 1 1 1 1Photostabilizer Sanol LS-765 1 1 1 1 Antioxidant Irganox 1010 1 1 1 1Dehydrating agent A-171 2 2 2 2 Adhesion-imparting agent A-1120 3 3 3 3Titanium diisopropoxidebis(ethylacetoacetate) TC-750 7.5 Titaniumtetraisopropoxide 5 Dibutyltinbis(acetylacetonate) U-220 1 1 Skinformation time (min) 270 400 83 75 Viscosity (Pa · s) 1 rpm 860 1,7802,020 1,100 2 rpm 540 1,020 1,180 680 10 rpm 190 320 370 240 Viscosityratio 2.8 3.2 3.2 2.8 (2 rpm/10 rpm) Workability B A A B

As shown in Table 1, in the case of using the organotin catalyst (U-220)as a curing catalyst (Comparative Examples 3 and 4), curability (skinformation time) does not depend on a kind of a thixotropy-impartingagent and is equal to each other. The composition (ComparativeExample 1) containing the titanium chelate (TC-750) of the component (B)and the hydrogenated castor oil type thixotropy-imparting agent is notgood in curability, is not sufficient in thixotropy and is inferior inworkability. Additionally, in the case of using titanium tetraalkoxideas a titanium catalyst other than the component (B) (Comparative Example2), curability is not satisfactory. On the other hand, only thecompositions (Examples 1 to 3) containing amide wax typethixotropy-imparting agent and the titanium chelate (TC-750) have bothof curability and thixotropy (workability) by using a nonorganotincatalyst.

1. A curable composition comprising: (A) a polyoxyalkylene polymerhaving a silicon-containing group being capable of crosslinking byforming siloxane bonds and/or a (meth)acrylate polymer having asilicon-containing group being capable of crosslinking by formingsiloxane bonds, (B) a titanium chelate represented by the followinggeneral formula (1) or (2), and (C) an amide wax typethixotropy-imparting agent. General formula (1):

wherein each of n R¹s is independently a substituted or unsubstitutedhydrocarbon group having 1 to 20 carbon atoms, each of (4-n) R²s isindependently hydrogen atom or a substituted or unsubstitutedhydrocarbon group having 1 to 20 carbon atoms, each of (4-n) A¹s and(4-n) A²s is independently —R³ or —OR³ where R³ is a substituted orunsubstituted hydrocarbon group having 1 to 20 carbon atoms, n is 1, 2or
 3. General formula (2):

wherein R², A¹ and A² are the same as defined above, R⁴ is a substitutedor unsubstituted divalent hydrocarbon group having 1 to 20 carbon atoms.2. The curable composition according to claim 1, wherein said polymer(A) is a polyoxypropylene polymer having a silicon-containing groupbeing capable of crosslinking by forming siloxane bonds and/or a(meth)acrylate polymer having a silicon-containing group being capableof crosslinking by forming siloxane bonds.
 3. The curable compositionaccording to claim 1, wherein the glass transition temperature of thepolymer (A) is not more than 20° C.
 4. The curable composition accordingto claim 1, wherein with respect to 100 parts by weight of the polymer(A), the titanium chelate (B) is contained in an amount of from 0.1 to20 parts by weight and the amide wax type thixotropy-imparting agent (C)is contained in an amount of from 0.1 to 20 parts by weight.
 5. Asealant comprising said curable composition according to claim
 1. 6. Anadhesive comprising said curable composition according to claim
 1. 7.The curable composition according to claim 2, wherein the glasstransition temperature of the polymer (A) is not more than 20° C.
 8. Thecurable composition according to claim 2, wherein with respect to 100parts by weight of the polymer (A), the titanium chelate (B) iscontained in an amount of from 0.1 to 20 parts by weight and the amidewax type thixotropy-imparting agent (C) is contained in an amount offrom 0.1 to 20 parts by weight.
 9. The curable composition according toclaim 3, wherein with respect to 100 parts by weight of the polymer (A),the titanium chelate (B) is contained in an amount of from 0.1 to 20parts by weight and the amide wax type thixotropy-imparting agent (C) iscontained in an amount of from 0.1 to 20 parts by weight.
 10. Thecurable composition according to claim 7, wherein with respect to 100parts by weight of the polymer (A), the titanium chelate (B) iscontained in an amount of from 0.1 to 20 parts by weight and the amidewax type thixotropy-imparting agent (C) is contained in an amount offrom 0.1 to 20 parts by weight.
 11. A sealant comprising said curablecomposition according to claim
 2. 12. A sealant comprising said curablecomposition according to claim
 3. 13. A sealant comprising said curablecomposition according to claim
 7. 14. An adhesive comprising saidcurable composition according to claim
 2. 15. An adhesive comprisingsaid curable composition according to claim
 3. 16. An adhesivecomprising said curable composition according to claim 7.